National Hurricane Center
This year the NHC has a new interactive map that gives information when you mouse over tropical features. This should prove to be a real time saver in what's shaping up as a busy season.
TCPOD (Tropical Cyclone Plan of the Day)
This is the daily CARCAH (Chief, Aerial Reconnaissance Coordination, All Hurricanes) product ordering air recon for the next day. Good to see who's going to be up. CARCAH is a small (3-person) office at NHC. Here's what it looks like.
Air Recon Data
More than anyone will ever need to know. Note that these are the raw observations and need to be combined with other data by the National Hurricane Center before they are safe for use in decisions regarding life and property.
NHC Advisory Archive
Good for tracking data or to see if an area had been affected on previous days.
53rd Weather Recon Site
Official web site for the Air Force Reserve "Hurricane Hunters" out of Biloxi, MS. Radio callsign is TEAL. It is likely that GULL either never existed or was used just briefly enough to create perpetual Internet folklore. TEAL is the one they use. Most comm is by satellite, but the front end can be heard on aero frequencies and the back end running patches through Air Force MARS on 13927 kHz.
NOAA Aircraft Operations Center
NOAA's WP-3D aircraft also do the "Hurricane Hunter" dropsonde missions inside the storms. They also operate a Gulfstream IV-SP which can drop instruments from high above hurricanes.
Hurricane tracking maps at Accuweather
Last year I got pretty good at tracking hurricanes just in Adobe Acrobat Pro, by layering line graphics over the PDF files of NHC's blank tracking maps from their site. This is kind of an expensive way to do it, though, if you don't already have the software for something else. Well, whatever. Anyway, this site has a lot of maps of smaller areas than the large "official" ones of entire oceans, allowing more detailed plotting as the hurricane nears landfall. You can get really Weather Channel on this stuff, though it's just as easy really to watch it on the Weather Channel.
U of W Tropical Cyclones
A comprehensive web page that pulls together links to a lot of satellite images, charts, and other hurricane products.
Weather Underground Tropical Page
Like the one above, only slicker and somewhat more "commercial" looking. Not saying this is good or bad, just saying it is. It also pulls together a lot of information.
Monday, July 21, 2008
Tropical Storm Dolly Advisory #5
000
WTNT34 KNHC 211454
TCPAT4
BULLETIN
TROPICAL STORM DOLLY ADVISORY NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042008
1100 AM EDT MON JUL 21 2008
...DOLLY NOW OVER THE WARM WATERS OF THE GULF OF MEXICO...
AT 1100 AM EDT...1500 UTC...A HURRICANE WATCH IS ISSUED FOR THE TEXAS COAST FROM BROWNSVILLE NORTHWARD TO PORT O'CONNOR. A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 36 HOURS.
AT 1100 AM EDT...A TROPICAL STORM WATCH IS ISSUED FOR THE TEXAS COAST FROM NORTH OF PORT O'CONNOR TO SAN LUIS PASS. A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 36 HOURS.
AT 1100 AM EDT...THE GOVERNMENT OF MEXICO HAS ISSUED A HURRICANE WATCH FROM RIO SAN FERNANDO MEXICO NORTHWARD TO THE U.S. BORDER...AND A TROPICAL STORM WATCH FROM LA PESCA MEXICO NORTHWARD TO RIO SAN FERNANDO.
A TROPICAL STORM WARNING REMAINS IN EFFECT FOR THE YUCATAN PENINSULA OF MEXICO FROM THE BORDER WITH BELIZE TO CAMPECHE MEXICO.
FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL WEATHER OFFICE.
AT 1100 AM EDT...1500Z...THE CENTER OF TROPICAL STORM DOLLY WAS LOCATED NEAR LATITUDE 22.1 NORTH...LONGITUDE 89.5 WEST OR ABOUT 55 MILES... 90 KM...NORTH-NORTHEAST OF PROGRESO MEXICO.
DOLLY IS MOVING TOWARD THE WEST-NORTHWEST NEAR 18 MPH...30 KM/HR. A GRADUAL DECREASE IN FORWARD SPEED IS FORECAST DURING THE NEXT COUPLE OF DAYS...WITH LITTLE CHANGE IN THE DIRECTION OF MOTION. ON THIS TRACK...DOLLY WILL BE APPROACHING THE COAST OF THE WESTERN GULF OF MEXICO BY WEDNESDAY.
MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/HR...WITH HIGHER GUSTS. STRENGTHENING IS FORECAST...AND DOLLY COULD BECOME A HURRICANE BY TOMORROW.
TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES...280 KM FROM THE CENTER.
THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON RECENT AIRCRAFT DATA IS 1005 MB...29.68 INCHES.
DOLLY IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF TWO TO FOUR INCHES ACROSS THE NORTHERN YUCATAN PENINSULA OF MEXICO WITH ISOLATED MAXIMUM AMOUNTS UP TO SIX INCHES.
REPEATING THE 1100 AM EDT POSITION...22.1 N...89.5 W. MOVEMENT TOWARD...WEST-NORTHWEST NEAR 18 MPH. MAXIMUM SUSTAINED WINDS...50 MPH. MINIMUM CENTRAL PRESSURE...1005 MB.
AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT 200 PM EDT FOLLOWED BY THE NEXT COMPLETE ADVISORY AT 500 PM EDT.
$$
FORECASTER KNABB
WTNT34 KNHC 211454
TCPAT4
BULLETIN
TROPICAL STORM DOLLY ADVISORY NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042008
1100 AM EDT MON JUL 21 2008
...DOLLY NOW OVER THE WARM WATERS OF THE GULF OF MEXICO...
AT 1100 AM EDT...1500 UTC...A HURRICANE WATCH IS ISSUED FOR THE TEXAS COAST FROM BROWNSVILLE NORTHWARD TO PORT O'CONNOR. A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 36 HOURS.
AT 1100 AM EDT...A TROPICAL STORM WATCH IS ISSUED FOR THE TEXAS COAST FROM NORTH OF PORT O'CONNOR TO SAN LUIS PASS. A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 36 HOURS.
AT 1100 AM EDT...THE GOVERNMENT OF MEXICO HAS ISSUED A HURRICANE WATCH FROM RIO SAN FERNANDO MEXICO NORTHWARD TO THE U.S. BORDER...AND A TROPICAL STORM WATCH FROM LA PESCA MEXICO NORTHWARD TO RIO SAN FERNANDO.
A TROPICAL STORM WARNING REMAINS IN EFFECT FOR THE YUCATAN PENINSULA OF MEXICO FROM THE BORDER WITH BELIZE TO CAMPECHE MEXICO.
FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL WEATHER OFFICE.
AT 1100 AM EDT...1500Z...THE CENTER OF TROPICAL STORM DOLLY WAS LOCATED NEAR LATITUDE 22.1 NORTH...LONGITUDE 89.5 WEST OR ABOUT 55 MILES... 90 KM...NORTH-NORTHEAST OF PROGRESO MEXICO.
DOLLY IS MOVING TOWARD THE WEST-NORTHWEST NEAR 18 MPH...30 KM/HR. A GRADUAL DECREASE IN FORWARD SPEED IS FORECAST DURING THE NEXT COUPLE OF DAYS...WITH LITTLE CHANGE IN THE DIRECTION OF MOTION. ON THIS TRACK...DOLLY WILL BE APPROACHING THE COAST OF THE WESTERN GULF OF MEXICO BY WEDNESDAY.
MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/HR...WITH HIGHER GUSTS. STRENGTHENING IS FORECAST...AND DOLLY COULD BECOME A HURRICANE BY TOMORROW.
TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES...280 KM FROM THE CENTER.
THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON RECENT AIRCRAFT DATA IS 1005 MB...29.68 INCHES.
DOLLY IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF TWO TO FOUR INCHES ACROSS THE NORTHERN YUCATAN PENINSULA OF MEXICO WITH ISOLATED MAXIMUM AMOUNTS UP TO SIX INCHES.
REPEATING THE 1100 AM EDT POSITION...22.1 N...89.5 W. MOVEMENT TOWARD...WEST-NORTHWEST NEAR 18 MPH. MAXIMUM SUSTAINED WINDS...50 MPH. MINIMUM CENTRAL PRESSURE...1005 MB.
AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT 200 PM EDT FOLLOWED BY THE NEXT COMPLETE ADVISORY AT 500 PM EDT.
$$
FORECASTER KNABB
Friday, July 18, 2008
Wednesday's Solar Flux Was NOT the Lowest!
An important correction to all the speculation on Wednesday's solar flux comes from the mailing list of Thomas F. Giella (KN4LF). After searching the data (available here), he's come up with a daily uncorrected 10.7 cm solar radio flux of 62.6 on November 3, 1954.
Personal examination of the data confirms this.
Of course, there is some debate regarding the validity of direct comparisons. Several variables exist, which are way too technical to get into here.
Yesterday's discussion of why solar fluxes adjust higher in summer and lower in winter still holds. The Earth's orbit is still at aphelion in July. That makes a November daily flux of 62.6 even more remarkable, since it adjusted downward to a phenomenal 61.6. No wonder the formula for flux vs sunspot numbers should be considered an approximation, since it doesn't allow anything lower than 67!!!
Those seeking any predictive value from Wednesday's low solar flux would be cautioned that less than four years later, in 1958, came the start of the highest solar maximum ever measured, with many uncorrected daily fluxes in the high 300's. While this does not change the fact that Cycle 24 is VERY late, we should remember that the sun will do what it wants to do.
Personal examination of the data confirms this.
Of course, there is some debate regarding the validity of direct comparisons. Several variables exist, which are way too technical to get into here.
Yesterday's discussion of why solar fluxes adjust higher in summer and lower in winter still holds. The Earth's orbit is still at aphelion in July. That makes a November daily flux of 62.6 even more remarkable, since it adjusted downward to a phenomenal 61.6. No wonder the formula for flux vs sunspot numbers should be considered an approximation, since it doesn't allow anything lower than 67!!!
Those seeking any predictive value from Wednesday's low solar flux would be cautioned that less than four years later, in 1958, came the start of the highest solar maximum ever measured, with many uncorrected daily fluxes in the high 300's. While this does not change the fact that Cycle 24 is VERY late, we should remember that the sun will do what it wants to do.
Thursday, July 17, 2008
"Digital" Mode of the Week: Slow-Scan TV
Like HF FAX, the rather misnamed "Slow Scan Television" mode is actually analog. However, it appears in most multimode packages intended for digital reception, and it is also one of the more fun things you can do with a radio and a computer.
I can't imagine anyone actually using SSTV to send continuous video frames, though the simpler black and white versions would at least be able to do a couple of these per minute rather than a couple of minutes per frame. The major use for SSTV is for amateurs to swap still photos. In fact, I can't think of any commercial applications for the SSTV mode on the radio. The closest would be the pictures sometimes sent down by ham radios on the International Space Station.
Old B/W SSTV was a kind of scaled-down (320x240), sped-up version of FAX. It, too, used frequency or audio-frequency modulation of a single carrier or tone over 800 Hz, with black at 1500 and white at 2300. For digital, the grey scale is quantized to 256 levels (8 bits), which are plenty.
One of the first innovations was to add color. This was first done by sending the three color channels sequentially in full frame. This didn't show the true colors until all three frames were received, a rather slow process. A later innovation was line-sequential mode. It typically sends each line three times, with one 1200-Hz, 5-ms, sync pulse at the start of the red line.
One of the early color modes was Robot, as originally done in dedicated hardware boxes with a huge "ROBOT" logo on the front. It really looked like something from science fiction, and cost like it too.
Out of the 30-some common SSTV modes still in existence, nearly all transmissions are in Martin 1 (114 sec for a 320x256 frame), Martin 2 (58 sec), Scottie 1 (110 sec), Scottie 2 (71 sec), and Scottie DX (268 sec). Martin 1 and 2 were developed by amateur Martin Emmerson, G3OQD, and they are common in Europe. Scottie was developed by another British ham, Eddie ("Scottie") Murphy, GM3SBC. Its modes are dominant in the United States and Japan.
SSTV can be tuned the same way as FAX, by centering the audio between the high and low lines on the computer display. It's trickier, but you can also center the sync pulse as close to 1200 as you can get it. Most programs have AFC if you're off a few hertz. The little picture will start to scan down its part of the screen. One of the nice things about most analog transfer modes is you can start in the middle, and that's possible here too.
SSTV software can auto-start, and also it can auto-mode, either by measuring the interval between sync pulses or reading a start burst called a VIS signal. The VIS consists of a 1200-Hz marker followed by a mode designator in FSK between 1100 and 1300 Hz. A similar optional code is sent at the end of a picture.
SSTV, like FAX, will be slanted proportional to the difference between your clock frequency and that of the sending station. Various programs cope with slant correction in various ways, usually by buffering the picture and allowing its adjustment in real time during reception. This can be manual or automatic. One program, MMSSTV, allows you to click on a happy face when you get a straight picture from a "trusted" station, locking in this correction.
By far the most active SSTV frequency is 14230 kHz USB, which really lights up on weekends, going also to 14228 when there's QRM. When 20 dies, there's lesser activity on 7171 kHz LSB, +/- a kHz or so. There's also spotty activity on 6 and 2 meter VHF. Oh, and some parts of the world have pirate SSTV networks outside the amateur bands, which exchange pictures that are far more X-rated than anything amateurs can get away with.
You might have heard of the even more misnamed "digital SSTV." It uses file transfer software to exchange data, which in this case just happens to be pictures. It's typically on 14233 kHz USB, using one particular, rather fussy and esoteric program. It looks great, but it requires a very high signal to noise and almost no fading.
One of the programs designed for this purpose is the same DIGTRX that the Cuban SK01 numbers station uses to send its weird little files. Woe betide any ham who transmits with this one on 14233, though, since it is not the OFFICIAL program mentioned above. You'll think you had a visit from the Wouff Hong. Don't hate ham radio, just come back to good old grungy noisy easy and fun analog.
I can't imagine anyone actually using SSTV to send continuous video frames, though the simpler black and white versions would at least be able to do a couple of these per minute rather than a couple of minutes per frame. The major use for SSTV is for amateurs to swap still photos. In fact, I can't think of any commercial applications for the SSTV mode on the radio. The closest would be the pictures sometimes sent down by ham radios on the International Space Station.
Old B/W SSTV was a kind of scaled-down (320x240), sped-up version of FAX. It, too, used frequency or audio-frequency modulation of a single carrier or tone over 800 Hz, with black at 1500 and white at 2300. For digital, the grey scale is quantized to 256 levels (8 bits), which are plenty.
One of the first innovations was to add color. This was first done by sending the three color channels sequentially in full frame. This didn't show the true colors until all three frames were received, a rather slow process. A later innovation was line-sequential mode. It typically sends each line three times, with one 1200-Hz, 5-ms, sync pulse at the start of the red line.
One of the early color modes was Robot, as originally done in dedicated hardware boxes with a huge "ROBOT" logo on the front. It really looked like something from science fiction, and cost like it too.
Out of the 30-some common SSTV modes still in existence, nearly all transmissions are in Martin 1 (114 sec for a 320x256 frame), Martin 2 (58 sec), Scottie 1 (110 sec), Scottie 2 (71 sec), and Scottie DX (268 sec). Martin 1 and 2 were developed by amateur Martin Emmerson, G3OQD, and they are common in Europe. Scottie was developed by another British ham, Eddie ("Scottie") Murphy, GM3SBC. Its modes are dominant in the United States and Japan.
SSTV can be tuned the same way as FAX, by centering the audio between the high and low lines on the computer display. It's trickier, but you can also center the sync pulse as close to 1200 as you can get it. Most programs have AFC if you're off a few hertz. The little picture will start to scan down its part of the screen. One of the nice things about most analog transfer modes is you can start in the middle, and that's possible here too.
SSTV software can auto-start, and also it can auto-mode, either by measuring the interval between sync pulses or reading a start burst called a VIS signal. The VIS consists of a 1200-Hz marker followed by a mode designator in FSK between 1100 and 1300 Hz. A similar optional code is sent at the end of a picture.
SSTV, like FAX, will be slanted proportional to the difference between your clock frequency and that of the sending station. Various programs cope with slant correction in various ways, usually by buffering the picture and allowing its adjustment in real time during reception. This can be manual or automatic. One program, MMSSTV, allows you to click on a happy face when you get a straight picture from a "trusted" station, locking in this correction.
By far the most active SSTV frequency is 14230 kHz USB, which really lights up on weekends, going also to 14228 when there's QRM. When 20 dies, there's lesser activity on 7171 kHz LSB, +/- a kHz or so. There's also spotty activity on 6 and 2 meter VHF. Oh, and some parts of the world have pirate SSTV networks outside the amateur bands, which exchange pictures that are far more X-rated than anything amateurs can get away with.
You might have heard of the even more misnamed "digital SSTV." It uses file transfer software to exchange data, which in this case just happens to be pictures. It's typically on 14233 kHz USB, using one particular, rather fussy and esoteric program. It looks great, but it requires a very high signal to noise and almost no fading.
One of the programs designed for this purpose is the same DIGTRX that the Cuban SK01 numbers station uses to send its weird little files. Woe betide any ham who transmits with this one on 14233, though, since it is not the OFFICIAL program mentioned above. You'll think you had a visit from the Wouff Hong. Don't hate ham radio, just come back to good old grungy noisy easy and fun analog.
Lowest Solar Flux Ever Measured?
Scientists can't decide if this depressing solar cycle just recorded the most depressingly low solar radio flux ever measured.
July 16's reading was a staggeringly low 64.2 sfu (solar flux units), according to the Canadian observatory which makes this measurement. If this holds up, it will be the lowest since this data series began around 1950.
The "Solar Flux" we talk about is an uncorrected measurement of solar radio noise taken three times daily, on a standard frequency of 2800 MHz (10.7 cm). This is an important frequency in radio astronomy, as it comes from a certain hyperfine quantum transition in hydrogen gas excited by solar magnetic flux that also causes "sunspots." It is a much newer data series than the "sunspot number" which is derived from a number of amateur observers worldwide who literally count spots on the sun's disk.
They haven't had much to count recently, as the sun is still in a very deep minimum at the end of a very long cycle (#23).
The most commonly used formula relating solar flux to sunspot numbers in an average case does not allow values lower than around 67, which is considered a completely quiet sun. However, lower values do occur in the daily uncorrected observations. Before this summer's reading, the record low was a 64.7 observed on July 18, 1996.
What's up here? Well, note that both lows were in mid-July, when the Earth is at aphelion (the farthest point from the sun). This wouldn't be an issue if the Earth's orbit were completely circular, but of course like most orbits it's slightly elliptical. Therefore the greatest downward deviation from the average quiet sun case is in summer - and that's when we read these low uncorrected solar fluxes. It's also why the solar flux is corrected to take the Earth's orbit into account.
Presumably when the corrected flux comes out, it'll be a little less depressing. Not a lot, but just a little.
July 16's reading was a staggeringly low 64.2 sfu (solar flux units), according to the Canadian observatory which makes this measurement. If this holds up, it will be the lowest since this data series began around 1950.
The "Solar Flux" we talk about is an uncorrected measurement of solar radio noise taken three times daily, on a standard frequency of 2800 MHz (10.7 cm). This is an important frequency in radio astronomy, as it comes from a certain hyperfine quantum transition in hydrogen gas excited by solar magnetic flux that also causes "sunspots." It is a much newer data series than the "sunspot number" which is derived from a number of amateur observers worldwide who literally count spots on the sun's disk.
They haven't had much to count recently, as the sun is still in a very deep minimum at the end of a very long cycle (#23).
The most commonly used formula relating solar flux to sunspot numbers in an average case does not allow values lower than around 67, which is considered a completely quiet sun. However, lower values do occur in the daily uncorrected observations. Before this summer's reading, the record low was a 64.7 observed on July 18, 1996.
What's up here? Well, note that both lows were in mid-July, when the Earth is at aphelion (the farthest point from the sun). This wouldn't be an issue if the Earth's orbit were completely circular, but of course like most orbits it's slightly elliptical. Therefore the greatest downward deviation from the average quiet sun case is in summer - and that's when we read these low uncorrected solar fluxes. It's also why the solar flux is corrected to take the Earth's orbit into account.
Presumably when the corrected flux comes out, it'll be a little less depressing. Not a lot, but just a little.
Wednesday, July 16, 2008
HF Jamming Network Adapters Now in US
Belkin has introduced the US version of the power line communications adapter that has been causing catastrophic HF interference in Europe and South America.
They're still claiming the 200 MB speed, which is dreaming for any real-world situations these things will ever be used in. While this borders on false advertising, it will sell a lot of these adapters to geeks.
More here.
The choice before this hobby is stark: get organized NOW or lose HF.
They're still claiming the 200 MB speed, which is dreaming for any real-world situations these things will ever be used in. While this borders on false advertising, it will sell a lot of these adapters to geeks.
More here.
The choice before this hobby is stark: get organized NOW or lose HF.
Saturday, July 12, 2008
New WLO Frequencies for Night of Nights IX
WLO
WLO will transmit on 2055.5, 4343.0, 8658.0, 12992.0 and 17022.5kc (no MF for WLO this year)
WLO will listen for calls from ships HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
WLO Radio
7700 RINLA AVENUE
MOBILE, ALABAMA 36619
USA
Full details here
WLO will transmit on 2055.5, 4343.0, 8658.0, 12992.0 and 17022.5kc (no MF for WLO this year)
WLO will listen for calls from ships HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
WLO Radio
7700 RINLA AVENUE
MOBILE, ALABAMA 36619
USA
Full details here
Friday, July 11, 2008
Latest UK PLC News
The situation is evolving fast with regard to home Ethernet power line adapters which create massive interference to HF in the UK.
"Mike in West Sussex" has finally made a connection with a real live human being someplace other than the Asian call center who works for BT and knows something:
BT is, of course, the big British telecom provider, following privatisation of what used to (I believe) be a government telcom company. Now, it's a huge communication conglomerate with a global reach, like any other big company. Those who deal with them report that it has essentially replaced a government bureaucracy with a corporate bureaucracy.
Ofcom is the British FCC, created when the regulation of telecom was removed from the old department within the Post Office. As with our FCC, its mandate seems to be evolving away from preventing harmful interference to licensed radio services, and towards doing whatever maximizes free competition in the marketplace.
By way of background, the BT Home Hub is the home router/modem for their high speed Internet connection service. The trouble is caused by the wall wart adapters that are sold with BT's video service, which sends on-demand video from the Home Hub to TVs elsewhere in the home. Some of these use the DS2 chipset, which can be notched to exclude ham bands, but is otherwise the most efficient HF jammer ever invented. It is completely out of compliance with European EMC regulations, and it has caused problems throughout the UK.
Apparently, BT will replace these, but the customer has to ask. Then the older ones show up on eBay, since at 99 British pounds a pair when new, they're not exactly throwaways.
It is becoming evident that the problem is caused by short wave listeners who do not want to become involved. The BPL/PLC "industry" is able to argue that its equipment is clean because "nobody complains." Obviously, people with problems have not made them known to the FCC and the companies behind this badly designed and misbegotten technology. I realize that HF utility listeners in particular tend to be very low-profile, given the various secrecy of communications laws. However, the stakes here involve the survival of the entire pastime. It's best to fight now, before it's all over.
"Mike in West Sussex" has finally made a connection with a real live human being someplace other than the Asian call center who works for BT and knows something:
Just had a phone call from one Julie O Sullivan who may be the BT Chairman's PA. She was calling in regard to the letter I sent him just yesterday!
Stated, very unusual never heard of this before, I am going to make some enquiries within BT.
I said that she may like to Google the problem in which case it would become apparent how wide spread it was.
She was insistent that I took her name and number down!
So finally I got a shot into the BT heart.
I'll keep you posted on any more developments.
Meantime, if anyone else here is suffering this QRM please report it today to Ofcom and write a letter to the BT Chairman about it. Do it today so that we all ride the storm its clearly stirring up!
BT is, of course, the big British telecom provider, following privatisation of what used to (I believe) be a government telcom company. Now, it's a huge communication conglomerate with a global reach, like any other big company. Those who deal with them report that it has essentially replaced a government bureaucracy with a corporate bureaucracy.
Ofcom is the British FCC, created when the regulation of telecom was removed from the old department within the Post Office. As with our FCC, its mandate seems to be evolving away from preventing harmful interference to licensed radio services, and towards doing whatever maximizes free competition in the marketplace.
By way of background, the BT Home Hub is the home router/modem for their high speed Internet connection service. The trouble is caused by the wall wart adapters that are sold with BT's video service, which sends on-demand video from the Home Hub to TVs elsewhere in the home. Some of these use the DS2 chipset, which can be notched to exclude ham bands, but is otherwise the most efficient HF jammer ever invented. It is completely out of compliance with European EMC regulations, and it has caused problems throughout the UK.
Apparently, BT will replace these, but the customer has to ask. Then the older ones show up on eBay, since at 99 British pounds a pair when new, they're not exactly throwaways.
It is becoming evident that the problem is caused by short wave listeners who do not want to become involved. The BPL/PLC "industry" is able to argue that its equipment is clean because "nobody complains." Obviously, people with problems have not made them known to the FCC and the companies behind this badly designed and misbegotten technology. I realize that HF utility listeners in particular tend to be very low-profile, given the various secrecy of communications laws. However, the stakes here involve the survival of the entire pastime. It's best to fight now, before it's all over.
Night Of Nights IX is THIS WEEKEND!
Night of Nights IX Information
HISTORIC MORSE CODE RADIO STATIONS RETURN TO THE AIR FOR "NIGHT OF NIGHTS IX"
o Stations KPH and KFS will return to the air!
o MRHS station KSM will be on the air.
o Coast Stations WLO, KLB, NMC, NOJ and NMN may join in.
o Amateur station K6KPH, with commercial operators at the key, will be QRV for signal reports.
o Operations begin at 1701pdt 12 July, 0001gmt 13 July. We usually continue two way operations for about 6 hours but broadcasts on the commercial stations KPH, KFS and KSM may continue after that.
Here is the frequency list:
KPH
KPH will transmit on 426, 500, 4247.0, 6477.5, 8642.0, 12808.5, 17016.8 and 22477.5kc. Transmitters on all HF channels except 22Mc will be classic 1950s vintage RCA sets.
These frequencies have been made available through the generous cooperation of Globe Wireless, the current owner of the KPH and KFS licenses.
KPH operators will listen for calls from ships on ITU Channel 3 in all bands. The Channel 3 frequencies are 4184.0, 6276.0, 8368.0, 12552.0, 16736.0 and 22280.5kc on HF and 500kc on MF.
Reception reports may be sent to:
Ms. DA Stoops
P.O. Box 381
Bolinas CA 94924-0381
USA
Denice is a former KPH operator and was the first female telegrapher hired at the station.
------------
KFS
KFS will transmit on 12695.5 and 17026.0kc. The transmitter for 12Mc will be a 1940s vintage Press Wireless PW-15.
KFS will listen for calls from ships on HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
Ms. DA Stoops
P.O. Box 381
Bolinas CA 94924-0381
USA
------------
KSM
KSM will transmit on 426, 500, 6474.0, 8438.3 and 12993.0kc.
(We don't have enough antennas to accommodate the other KSM frequencies when KPH and KFS are on the air)
KSM will listen for calls from ships on 500kc and HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
Ms. DA Stoops
P.O. Box 381
Bolinas CA 94924-0381
USA
------------
WLO
WLO will transmit on 438, 500 (MF not yet confirmed), 4343.0, 8658.0, 12992.0kc
WLO will listen for calls from ships on 500kc (not confirmed) and HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
WLO Radio
7700 RINLA AVENUE
MOBILE, ALABAMA 36619
USA
------------
KLB
KLB will transmit on 488, 500 (A1 & A2), 2063.0 and 8582.5kc
KLB will listen for calls from ships on 500kc and 8368.0kc.
Reception reports may be sent to:
WLO Radio
7700 RINLA AVENUE
MOBILE, ALABAMA 36619
USA
------------
NMN
NMN will transmit on 448, 468, 500, 8471.0, 12718.5 and 16976.0kc
NMN will listen for calls from ships on 500kc and HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
COMMANDING OFFICER
U. S. COAST GUARD COMMUNICATION AREA MASTER
STATION ATLANTIC (CAMSLANT)
4720 DOUGLAS A. MUNRO ROAD
CHESAPEAKE, VIRGINIA, USA 23322
ATTN: CWO VERN TUSS
------------
NMC
NMC will transmit on 448, 472, 500, 6383.0, 8574.0 and 17220.5kc
NMC will listen for calls from ships on 500kc and HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
COMMANDING OFFICER
ATTN: ITC ERIC SIMMONS
COMMUNICATIONS AREA MASTER STATION PACIFIC
17000 SIR FRANCIS DRAKE BLVD
POINT REYES STATION, CALIFORNIA 94956-0560
USA
------------
NOJ
NOJ will transmit on 416, 470, 500, 8650.0, 12889.5 and 16909.7kc and 16909.7kc.
NOJ will listen for calls from ships on Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
COMMANDING OFFICER
ATTN: OSCM DAN LAWLER
US COAST GUARD COMMUNICATIONS STATION KODIAK
PO BOX 190017
KODIAK, ALASKA 99619
USA
------------
K6KPH
Amateur station K6KPH will transmit and listen on 3550, 7050 and 14050kc for KPH, KFS and KSM reception reports.
Professional operators will be at the key and commercial procedures will be used. But please don't hesitate to call, no matter what your code speed or experience level may be.
[In practice, the main surprise for hams is that "DE" means about the same thing as "QRZ?" The op sends DE when he/she wants to hear your callsign again. You don't have to send theirs. Kind of like DX pileup procedure.]
K6KPH verification reports may be sent to:
Ms. DA Stoops
P.O. Box 381
Bolinas CA 94924-0381
USA
[DO get their QSL, on the radiogram blank...]
HISTORIC MORSE CODE RADIO STATIONS RETURN TO THE AIR FOR "NIGHT OF NIGHTS IX"
o Stations KPH and KFS will return to the air!
o MRHS station KSM will be on the air.
o Coast Stations WLO, KLB, NMC, NOJ and NMN may join in.
o Amateur station K6KPH, with commercial operators at the key, will be QRV for signal reports.
o Operations begin at 1701pdt 12 July, 0001gmt 13 July. We usually continue two way operations for about 6 hours but broadcasts on the commercial stations KPH, KFS and KSM may continue after that.
Here is the frequency list:
KPH
KPH will transmit on 426, 500, 4247.0, 6477.5, 8642.0, 12808.5, 17016.8 and 22477.5kc. Transmitters on all HF channels except 22Mc will be classic 1950s vintage RCA sets.
These frequencies have been made available through the generous cooperation of Globe Wireless, the current owner of the KPH and KFS licenses.
KPH operators will listen for calls from ships on ITU Channel 3 in all bands. The Channel 3 frequencies are 4184.0, 6276.0, 8368.0, 12552.0, 16736.0 and 22280.5kc on HF and 500kc on MF.
Reception reports may be sent to:
Ms. DA Stoops
P.O. Box 381
Bolinas CA 94924-0381
USA
Denice is a former KPH operator and was the first female telegrapher hired at the station.
------------
KFS
KFS will transmit on 12695.5 and 17026.0kc. The transmitter for 12Mc will be a 1940s vintage Press Wireless PW-15.
KFS will listen for calls from ships on HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
Ms. DA Stoops
P.O. Box 381
Bolinas CA 94924-0381
USA
------------
KSM
KSM will transmit on 426, 500, 6474.0, 8438.3 and 12993.0kc.
(We don't have enough antennas to accommodate the other KSM frequencies when KPH and KFS are on the air)
KSM will listen for calls from ships on 500kc and HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
Ms. DA Stoops
P.O. Box 381
Bolinas CA 94924-0381
USA
------------
WLO
WLO will transmit on 438, 500 (MF not yet confirmed), 4343.0, 8658.0, 12992.0kc
WLO will listen for calls from ships on 500kc (not confirmed) and HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
WLO Radio
7700 RINLA AVENUE
MOBILE, ALABAMA 36619
USA
------------
KLB
KLB will transmit on 488, 500 (A1 & A2), 2063.0 and 8582.5kc
KLB will listen for calls from ships on 500kc and 8368.0kc.
Reception reports may be sent to:
WLO Radio
7700 RINLA AVENUE
MOBILE, ALABAMA 36619
USA
------------
NMN
NMN will transmit on 448, 468, 500, 8471.0, 12718.5 and 16976.0kc
NMN will listen for calls from ships on 500kc and HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
COMMANDING OFFICER
U. S. COAST GUARD COMMUNICATION AREA MASTER
STATION ATLANTIC (CAMSLANT)
4720 DOUGLAS A. MUNRO ROAD
CHESAPEAKE, VIRGINIA, USA 23322
ATTN: CWO VERN TUSS
------------
NMC
NMC will transmit on 448, 472, 500, 6383.0, 8574.0 and 17220.5kc
NMC will listen for calls from ships on 500kc and HF Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
COMMANDING OFFICER
ATTN: ITC ERIC SIMMONS
COMMUNICATIONS AREA MASTER STATION PACIFIC
17000 SIR FRANCIS DRAKE BLVD
POINT REYES STATION, CALIFORNIA 94956-0560
USA
------------
NOJ
NOJ will transmit on 416, 470, 500, 8650.0, 12889.5 and 16909.7kc and 16909.7kc.
NOJ will listen for calls from ships on Channel 3 (see KPH listing for frequencies).
Reception reports may be sent to:
COMMANDING OFFICER
ATTN: OSCM DAN LAWLER
US COAST GUARD COMMUNICATIONS STATION KODIAK
PO BOX 190017
KODIAK, ALASKA 99619
USA
------------
K6KPH
Amateur station K6KPH will transmit and listen on 3550, 7050 and 14050kc for KPH, KFS and KSM reception reports.
Professional operators will be at the key and commercial procedures will be used. But please don't hesitate to call, no matter what your code speed or experience level may be.
[In practice, the main surprise for hams is that "DE" means about the same thing as "QRZ?" The op sends DE when he/she wants to hear your callsign again. You don't have to send theirs. Kind of like DX pileup procedure.]
K6KPH verification reports may be sent to:
Ms. DA Stoops
P.O. Box 381
Bolinas CA 94924-0381
USA
[DO get their QSL, on the radiogram blank...]
Tuesday, July 08, 2008
More Google Earth Fun
We haven't done this in a while.
34.571709,33.005896
This is yet another candidate for the Lincolnshire Poacher site on Cyprus. Thanks to Simon Mason for these coordinates. They put you inside a fenced compound with radomes to the southwest and apparent antenna towers everywhere else. As always, antennas don't really show up well, but their shadows do.
Most interesting is the building at the northeast which appears connected to an amazing log periodic farm. I found seven huge beam antennas, and an eighth might be dimly visible. One feeder obviously goes under the fence and continues to two of these towers.
26.982789,-80.107938
Simon Mason's numbers radio site provided these coordinates too. They are bang in the middle of the Jonathan-Dickinson Missile Tracking Annex, an Eastern Test Range activity using a number of high-gain dishes to pick up telemetry from birds leaving Cape Canaveral. More interesting are the two antenna towers next to the largest building, and a number of other masts around the facility. Some of these are undoubtedly for lightning protection.
Most interesting of all, though, is the large feeder that comes out of the ground due east of this building. It leads eastward for a good distance across a swampy area, crosses SE Pinegrove St., and finally ends up at a fenced-off triangular area right next to the main highway. Here, there's a tall tower, again visible mostly from its shadow, though obstruction paint can also be made out. This is most likely the infamous Jupiter Inlet site that was suggested by the late Havana Moon and others as one source of the now defunct E5 "Cynthia" numbers broadcasts in 4-number groups with the test count at the beginning. These haven't been heard since 2003.
32.593841,-117.127399
Look quick, it's the giant AN/FRD-10 US Navy Wullenweber CDAA antenna at the Imperial Beach site. You can see this thing for miles up and down the Coronado Strand. It was decommissioned in 1999, and it may not be up for very much longer.
The antenna was used for direction finding in the cold war. Judging from the current photo taken in 2003, it's now used mostly for a parking lot. These huge arrays were built all over the world. Many have been taken down, leaving huge circles in the ground. These are now mistaken by Google Earth users for crop circles, weird Pagan religious sites, and ?????. I wonder what archaeologists will think when they stumble upon them 1000 years hence.
46°31'48.97"N,30°33'39.07"E
Russia's version of the CDAA is the Krug, also for direction finding. Here's a nice one outside Odessa.
40°40'41.48"N,105° 2'46.93"W
WWV, north of Ft. Collins, CO, in between several small lakes. The building to the southwest is for WWVB's two transmitters, each feeding a separate diamond-shaped antenna held up by four tall towers each, supporting two large, top-loaded, wire top-hat verticals for 60 kHz. The radiating elements to this aren't visible, but the two matching-coil doghouses with the loopy roads leading out from the building are. I'll bet the residential areas around here don't have any trouble getting their "atomic" clocks to acquire a signal!
The building to the northeast with two satellite dishes in front is for WWV. Feeders lead out to various towers supporting omnidirectional counterpoised verticals for 2.5, 5, 10, 15, and 20 MHz. Yes, there are more than 5 antennas visible. ??????
34.571709,33.005896
This is yet another candidate for the Lincolnshire Poacher site on Cyprus. Thanks to Simon Mason for these coordinates. They put you inside a fenced compound with radomes to the southwest and apparent antenna towers everywhere else. As always, antennas don't really show up well, but their shadows do.
Most interesting is the building at the northeast which appears connected to an amazing log periodic farm. I found seven huge beam antennas, and an eighth might be dimly visible. One feeder obviously goes under the fence and continues to two of these towers.
26.982789,-80.107938
Simon Mason's numbers radio site provided these coordinates too. They are bang in the middle of the Jonathan-Dickinson Missile Tracking Annex, an Eastern Test Range activity using a number of high-gain dishes to pick up telemetry from birds leaving Cape Canaveral. More interesting are the two antenna towers next to the largest building, and a number of other masts around the facility. Some of these are undoubtedly for lightning protection.
Most interesting of all, though, is the large feeder that comes out of the ground due east of this building. It leads eastward for a good distance across a swampy area, crosses SE Pinegrove St., and finally ends up at a fenced-off triangular area right next to the main highway. Here, there's a tall tower, again visible mostly from its shadow, though obstruction paint can also be made out. This is most likely the infamous Jupiter Inlet site that was suggested by the late Havana Moon and others as one source of the now defunct E5 "Cynthia" numbers broadcasts in 4-number groups with the test count at the beginning. These haven't been heard since 2003.
32.593841,-117.127399
Look quick, it's the giant AN/FRD-10 US Navy Wullenweber CDAA antenna at the Imperial Beach site. You can see this thing for miles up and down the Coronado Strand. It was decommissioned in 1999, and it may not be up for very much longer.
The antenna was used for direction finding in the cold war. Judging from the current photo taken in 2003, it's now used mostly for a parking lot. These huge arrays were built all over the world. Many have been taken down, leaving huge circles in the ground. These are now mistaken by Google Earth users for crop circles, weird Pagan religious sites, and ?????. I wonder what archaeologists will think when they stumble upon them 1000 years hence.
46°31'48.97"N,30°33'39.07"E
Russia's version of the CDAA is the Krug, also for direction finding. Here's a nice one outside Odessa.
40°40'41.48"N,105° 2'46.93"W
WWV, north of Ft. Collins, CO, in between several small lakes. The building to the southwest is for WWVB's two transmitters, each feeding a separate diamond-shaped antenna held up by four tall towers each, supporting two large, top-loaded, wire top-hat verticals for 60 kHz. The radiating elements to this aren't visible, but the two matching-coil doghouses with the loopy roads leading out from the building are. I'll bet the residential areas around here don't have any trouble getting their "atomic" clocks to acquire a signal!
The building to the northeast with two satellite dishes in front is for WWV. Feeders lead out to various towers supporting omnidirectional counterpoised verticals for 2.5, 5, 10, 15, and 20 MHz. Yes, there are more than 5 antennas visible. ??????
Sunday, July 06, 2008
PLC Links - Get Educated and Fight!
A new Yahoo! group and mailing list have been established for BT Vision/ HomePlug/ PLC interference victims in the UK, and anyone else worldwide who wants to help formulate strategies for preserving the HF listening hobby in all countries. It is at:
http://tech.groups.yahoo.com/group/UKQRM/
Other Links:
British Telecom
BT Vision (all this trouble for us, so people can watch Desperate Housewives in the bedroom)
BT Group Wiki Entry (we're a long way from the post office!)
BT Vision Wiki Entry
Typical UK interference problem
British OfCom Investigations
Taiwanese mfr of the DH-10PF
AcBel spec sheet
Why the 200 MB claim by the mfr AND in the BT web store is false advertising
The BPL/PLC industry's side of the story
What the interference sounds like
OfCom complaint web page
Severe interference in Hobart, Australia (YouTube video)
http://tech.groups.yahoo.com/group/UKQRM/
Other Links:
British Telecom
BT Vision (all this trouble for us, so people can watch Desperate Housewives in the bedroom)
BT Group Wiki Entry (we're a long way from the post office!)
BT Vision Wiki Entry
Typical UK interference problem
British OfCom Investigations
Taiwanese mfr of the DH-10PF
AcBel spec sheet
Why the 200 MB claim by the mfr AND in the BT web store is false advertising
The BPL/PLC industry's side of the story
What the interference sounds like
OfCom complaint web page
Severe interference in Hobart, Australia (YouTube video)
Friday, July 04, 2008
HomePlug/ PLC no stranger to ARRL
It appears that certain modest efforts have been made to protect US amateurs from this assault on HF radio. Unfortunately, these do not cover the rest of HF, and also (according to UK listeners), they don't prevent all of the noise, just the loudest stuff.
Here's something from ARRL:
It seems evident that we must now create a similar problem for these manufacturers. It is NOT OK to shift the problem onto other radio services that aren't as well organized. We need this technology OFF HF!
Here's something from ARRL:
Even if measurements are made correctly at 30 meters, the absolute maximum limits in the Part 15 rules are high enough that harmful interference is likely. Those S9+ level signals from otherwise legal Part 15 radiators would cause harmful interference to almost all received amateur signals.
Although a manufacturer is responsible only for meeting those limits, in many cases, they end up assuming some responsible for harmful interference on behalf of their customers. As a minimum, there are very real costs associated with dealing with interference complaints, and as word of mouth about widespread interference spreads, it could well have an effect on product sales.
Many trade associations for similar products have recognized the need to offer additional protection to radio services that might be found near their products. For systems deployed in residential neighborhoods, it is quite likely that these systems will have nearby amateur radio operators.
Over the past few years, ARRL has worked closely and productively with several of these organizations. As a result of joint testing performed with ARRL, HomePlug has chosen to include a spectral mask (notches) in the HF ham bands. (There were a number of amateurs on the HomePlug working groups who well understood why it was in their employer’s best interests to avoid widespread interference from their products.)
Although there is still some potential for interference, the specification has reduced their signal levels in the ham bands about 30 dB below what is required under Part 15. HomePlug chose to add the spectral masks to avoid the potential for widespread harmful interference to Amateur Radio in areas near HomePlug systems.
It seems evident that we must now create a similar problem for these manufacturers. It is NOT OK to shift the problem onto other radio services that aren't as well organized. We need this technology OFF HF!
Thursday, July 03, 2008
More on the enemy - it's the Universal Powerline Assn
Here's what we are up against. Thanks to Wikipedia (boldface mine):
Anyone who thinks this trend is peculiar to the UK has not been following developments in this technology. Hundreds of thousands of these adapters are being deployed all over Europe.
From Eurocom:
Here's more on the UPA, which is the enemy:
Here is the FAQ on the UPA's own site. It makes the magnitude of the struggle facing us only too stark.
It should be obvious to everyone that this technology is starting to deploy worldwide. While we worried about power companies putting RF into their lines, we missed telephone companies putting it into home wiring. We have catching up to do. It is best that we do it, or there will be no more HF.
The BT Vision Box is a rebranded Philips DIT9719 operating Microsoft Mediaroom software, and requires the BT Home Hub and BT Broadband internet. That said, a number of customers are using alternatives to the BT Home Hub without problems[citation needed].
The set-top box is connected to the hub via an ethernet cable either connected directly to the BT Home Hub, or to one of a pair of Comtrend UPA (Universal Powerline Association) compliant Ethernet adapters. The Comtrend UPA adaptors use the mains wiring in a house to create an ethernet network. A second adaptor is plugged into the mains and connected to the BT Home Hub via an ethernet cable. These plugs are provided as part of the BT Vision package. Additional Comtrend adaptors are available from BT so that a local area network can be created in the users home.
Anyone who thinks this trend is peculiar to the UK has not been following developments in this technology. Hundreds of thousands of these adapters are being deployed all over Europe.
From Eurocom:
15 October, 2007 13:59
Comtrend delivers 590,000 PLC solutions for Europe in 2007
Comtrend Corporation, a network solutions manufacturer and broadband, VoIP and data networks technologies specialist, has announced the delivery of 590,000 200-Mbps PLC Ethernet adapters, the PowerGrid DH-10PF, by the end of 2007. The solutions will be supplied to the English, Spanish and Portuguese markets respectively, making Comtrend the first international manufacturer capable of delivering such a high volume of PLC Ethernet adapters.
[Similar problems are reported by radio users in Spain and Portugal. -hugh]
In 2006, Comtrend Corporation also opened an office in Central Europe and confirmed its development in several countries within Northern Europe.
Developed in partnership with DS2, a PLC solutions specialist, Comtrend's PowerGrid DH-10PF establishes broadband home networks for sharing data, sound and high-definition TV content. In compliance with the 200-Mbps PLC standard supported by the UPA (Universal Powerline Association), to which Comtrend and DS2 belong, the DS2 PLC technology built into the PowerGrid DH-10PF helps to provide a solution cutting out dead spots, while delivering the speed and quality of service required for distributing video throughout the home.
Here's more on the UPA, which is the enemy:
• Universal Powerline Association (UPA)
– The Universal Powerline Association (UPA) is an International association working to harmonize global standards and regulations in the fast developing power line communications market. Power Line Communications (PLC) is a technology that utilizes existing electrical distribution lines, whether in-building or out in the
utility’s distribution system, for delivering high-speed communications services
– www.upaplc.org
• Wide Alliance of Industry Support
– Predominantly used in Europe and South America
– Single source vendor today (DS2)
– Alliance consist of silicon manufacture, system operators and system integrators
• Field Proven Home Networking Technology
– Over one million PLC chips shipped
– Selected by Belgacom, British Telecom, Telecom Italia & Telefonica as the main home networking technology
Here is the FAQ on the UPA's own site. It makes the magnitude of the struggle facing us only too stark.
It should be obvious to everyone that this technology is starting to deploy worldwide. While we worried about power companies putting RF into their lines, we missed telephone companies putting it into home wiring. We have catching up to do. It is best that we do it, or there will be no more HF.
HF: Defend It or Lose It!
I have never been more serious than right now. The use of HF radio is OVER unless all of us organize and fight with a single voice.
The situation:
Everyone wants high speed Internet access and digital video on demand. The current Internet cannot carry all this information. Whoever solves this problem will become very wealthy indeed, and will also have made a major contribution.
Unfortunately, in the rush to open up new information pipelines, a number of ill-conceived or self-serving schemes have emerged. For our purposes in the radio hobby, the worst of these is communication using power lines, which almost always involves putting wideband RF energy into ready-made antennas by any other name.
We haven't learned to live with BPL (Broadband Over Power Lines) yet, but now there is a far worse problem. It's PLC (Power Line Communication), and it's taking off like wildfire in Europe and South America. It's supported by the United Powerline Association, a global industry association with several very powerful and influential corporate members.
The first I knew that anything had gone badly, nightmarishly wrong was when two of this column's contributors in the UK suddenly stopped doing radio altogether. They reported huge blasts of high-pitched noise, hash, and general crud blanketing everything pretty much from DC to daylight.
Since this was new to the UK, it took a while to figure out what was going on there. What's happening is that British Telecom (BT; a phone company that also operates HF comm sites, and thus should know better) is providing its customers with power line adapters which send Ethernet through the house wiring. Not the power company's lines, but the wires in your house.
You plug one adapter from the Internet/Video on Demand box (called a BT Home Hub) into the power line, and plug in the second one near a television you want to use for the video.
It is probably well known to most technically aware people that Ethernet is basically RF. These adapters are broadband HF transmitters which turn your house into a giant radio station which can radiate hundreds of feet.
These are being made by the usual companies, and being widely promoted as the solution to the previous expense of running Ethernet cables through homes. These things will undoubtedly spread worldwide if they are not stopped right now.
The future:
It's not hard to imagine the result of millions of these gadgets being installed all over populated areas. The side effect will be the worldwide deployment the most effective HF jammer ever invented. It will create vast areas in our populated regions that are little more than HF exclusion zones. The HF spectrum, which used to belong to the public by way of its national and international licensing bodies, will have been hijacked!
As long as there's a buck to be made, there will be influential people and companies seeking to send RF through any available conductors for computer networking and digital media. Wires were designed to conduct electricity, fence off property, etc etc. They were never intended to be used in place of cable or Cat5 twisted pair. When used in this manner, they become antennas. It's simple physics.
The only conclusion:
HF is over unless we fight for it. As a hobby, we must become as united as the corporations we need to fight. We must make it clear that denying the use of internationally regulated radio services so that someone else can profit from cheap, badly designed consumer electronics is NEVER all right - EVER.
Let's get started.
The situation:
Everyone wants high speed Internet access and digital video on demand. The current Internet cannot carry all this information. Whoever solves this problem will become very wealthy indeed, and will also have made a major contribution.
Unfortunately, in the rush to open up new information pipelines, a number of ill-conceived or self-serving schemes have emerged. For our purposes in the radio hobby, the worst of these is communication using power lines, which almost always involves putting wideband RF energy into ready-made antennas by any other name.
We haven't learned to live with BPL (Broadband Over Power Lines) yet, but now there is a far worse problem. It's PLC (Power Line Communication), and it's taking off like wildfire in Europe and South America. It's supported by the United Powerline Association, a global industry association with several very powerful and influential corporate members.
The first I knew that anything had gone badly, nightmarishly wrong was when two of this column's contributors in the UK suddenly stopped doing radio altogether. They reported huge blasts of high-pitched noise, hash, and general crud blanketing everything pretty much from DC to daylight.
Since this was new to the UK, it took a while to figure out what was going on there. What's happening is that British Telecom (BT; a phone company that also operates HF comm sites, and thus should know better) is providing its customers with power line adapters which send Ethernet through the house wiring. Not the power company's lines, but the wires in your house.
You plug one adapter from the Internet/Video on Demand box (called a BT Home Hub) into the power line, and plug in the second one near a television you want to use for the video.
It is probably well known to most technically aware people that Ethernet is basically RF. These adapters are broadband HF transmitters which turn your house into a giant radio station which can radiate hundreds of feet.
These are being made by the usual companies, and being widely promoted as the solution to the previous expense of running Ethernet cables through homes. These things will undoubtedly spread worldwide if they are not stopped right now.
The future:
It's not hard to imagine the result of millions of these gadgets being installed all over populated areas. The side effect will be the worldwide deployment the most effective HF jammer ever invented. It will create vast areas in our populated regions that are little more than HF exclusion zones. The HF spectrum, which used to belong to the public by way of its national and international licensing bodies, will have been hijacked!
As long as there's a buck to be made, there will be influential people and companies seeking to send RF through any available conductors for computer networking and digital media. Wires were designed to conduct electricity, fence off property, etc etc. They were never intended to be used in place of cable or Cat5 twisted pair. When used in this manner, they become antennas. It's simple physics.
The only conclusion:
HF is over unless we fight for it. As a hobby, we must become as united as the corporations we need to fight. We must make it clear that denying the use of internationally regulated radio services so that someone else can profit from cheap, badly designed consumer electronics is NEVER all right - EVER.
Let's get started.
No New HFDL Ground Station
I'm receiving New York squitters now, but there is no mention of a new ground station, and others report that it is no longer being sent. Perhaps confusion in the HFDL system, now resolved?
New HFDL Ground Station?
Nothing from ARINC, but several HFDL ground stations are mentioning a new ground station called UNKNOWN in their squitters. Unfortunately, the closest one to The Land That Short Wave Forgot is New York, and there's not propagation from there yet. We'll try to get some more information.
Tuesday, July 01, 2008
CW Night of Nights in 11 days!
The annual Maritime Radio Historical Society "Night of Nights" event is less than one month [two weeks now -hugh] away.
Every year on 12 July (US time) many famous coast stations return to the air to commemorate the closure of commercial Morse in the USA. This year stations KPH, KFS, KSM and KLB have confirmed they will be on the air. We hope that US Coast Guard stations NMC, NOJ and NMN will join us as they did last year.
Amateur station K6KPH will guard 3550, 7050 and 14050kc for reception reports.
Preliminary information has been posted on the MRHS Web site: http://www.radiomarine.org
Check back often for updated information as it becomes available.
If you would like to receive announcements like this and are not already a member of our mailing list just send a message to: radiomarine-subscribe@yahoogroups.com
VY 73,
RD
=================================
Richard Dillman, W6AWO
Chief Operator, Coast Station KSM
Maritime Radio Historical Society
http://www.radiomarine.org
=================================
Thursday, June 26, 2008
"Digital" Mode of the Week: HF FAX
FAX stands for facsimile, or in this case radiofacsimile. Unlike the more recently developed office FAX machines used over wire telephone circuits, it is completely analog, using FM emission (F3C). It dates from work done by various inventors in the late 19th and early 20th centuries to send pictures over telegraph and later radio.
HF FAX was very widely used in the 20th century to send news photos and even entire newspapers over HF point to point circuits. Machines used huge drum scanners and similar drums to print at the other end. They were very precise, and very, very expensive. Now it can be done with simple computer sound card software, though at considerable loss of precision in this rather fussy mode.
Today's HF FAX uses a continuous FM carrier with a narrow 800-Hz deviation. Usually, anything around 1500 Hz, the lower limit, is reproduced as black, with the brightness increasing until it reaches a white point up around the high limit of 2300 Hz. By ear, fax can make a number of different sounds, but usually it makes a cyclic pulsing with a high-pitched shreik underneath.
Nowadays, instead of using true FM transmitters, the corresponding baseband audio tone is sent to a normal, single-sideband, suppressed-carrier, HF transmitter. The result sounds the same, only displaced in frequency due to the offset from the missing carrier. FAX is tuned in USB, or else it will reproduce as a negative, and the dial should read 1.9 kHz (the tone center) lower than published frequencies. Most of the time, one centers the waterfall display between two marks, and it's tuned in. Slight mistuning has no effect except to possibly wash out the blacks or whites, depending on which direction it is.
Two other parameters are essential for the reception of FAX. The first is called drum speed, though obviously nowadays transmission speed would be a better name. It's expressed in lines per minute. The receiving software must sync to this speed, or the pictures will not reproduce properly.
Far, far the most common speed is 120 LPM. It is used for nearly all weather FAX. Some more complex pictures are sent at 60 LPM, a speed which can sound like a time signal.
The second parameter is Index of Cooperation (IOC), expressed as an integer. This is a really arcane thing also dating from the use of drum scanners. It measures the resolution of the FAX. Nobody really has to know what the IOC measures, just what the number is, and it is nearly always 576. On very rare occasion, it's 288. This is way less important for computer screens than it is for rotating drums.
Those who are really curious as to just what the Index of Cooperation is will be pleased to know that it's commonly defined as the product of the total line length and the number of lines per unit length, divided by Pi. It's measuring the ratio of how much distance the scan steps for a new line to the diameter of the drum. The length of time any single FAX can last is determined proportional to the IOC. At 120/576, the standard weather format, this is 18.8 minutes, which is plenty. Going to 60/576 doubles this, along with increasing resolution, though of course the fax takes twice as long to send.
Now it's all clear, right? :-)
Most FAX software allows the setting of black and white or continuous tone (grey scale) modes. Except for satellite weather images, just about every FAX sent on HF nowadays is in black and white. I'll get some argument here, but I've always just kept it on continuous anyway. Otherwise lines get kind of jagged, and typical HF ionospheric multipath fuzz can get grungy looking in a hurry. Plus you have to change it whenever a satellite image is sent, and then change it back again.
Radiofax typically uses a standard called APT (Automatic Picture Transmission). This allows the unattended reception of faxes. Different bands and services use different versions of this, but the one we're interested in is as follows:
5 sec Start Tone (alternate black and white at 300 Hz)
Phasing (30 seconds of white with one black pulse per line)
Image (may have a white interval for sync)
5 sec Stop Tone (alternate black and white at 450 Hz)
Optional 10 sec black
Different agencies have slight variations on this, and these are usually just enough to confuse amateur software. Even so, one will notice that all the information needed to set parameters and receive faxes is here, except maybe for IOC and that's almost always 576 anyway.
Why more computer programs don't take advantage of this is beyond me. They don't however, and so your received fax is usually displaced (left edge is somewhere else in the screen) and slanted (computer is not printing lines at the exact speed of transmission). There are nearly always ways to fix these, either during or after reception.
Slant is way the more annoying of the two, because computer sound cards really aren't up to the task. They don't have the tight frequency tolerance that an expensive dedicated device would have. Typically, the proper slant compensation has to be found manually for a given station, and then it will vary for others, or even change during a long FAX.
I like FAX because it's radio with pictures. One learns how to read the weather charts pretty fast. They're not that different than the ones on the Weather Channel. Also, the satellite images are as good as the ones on your local TV, and better if you get into colorized WEFAX downlinking on higher frequencies.
Many coast guards and weather offices still send hours of these a day, and since they are being used by boats for serious navigation and safety of life at sea, they won't go away any time soon. Check the various lists and radio loggings for something audible in your area.
HF FAX was very widely used in the 20th century to send news photos and even entire newspapers over HF point to point circuits. Machines used huge drum scanners and similar drums to print at the other end. They were very precise, and very, very expensive. Now it can be done with simple computer sound card software, though at considerable loss of precision in this rather fussy mode.
Today's HF FAX uses a continuous FM carrier with a narrow 800-Hz deviation. Usually, anything around 1500 Hz, the lower limit, is reproduced as black, with the brightness increasing until it reaches a white point up around the high limit of 2300 Hz. By ear, fax can make a number of different sounds, but usually it makes a cyclic pulsing with a high-pitched shreik underneath.
Nowadays, instead of using true FM transmitters, the corresponding baseband audio tone is sent to a normal, single-sideband, suppressed-carrier, HF transmitter. The result sounds the same, only displaced in frequency due to the offset from the missing carrier. FAX is tuned in USB, or else it will reproduce as a negative, and the dial should read 1.9 kHz (the tone center) lower than published frequencies. Most of the time, one centers the waterfall display between two marks, and it's tuned in. Slight mistuning has no effect except to possibly wash out the blacks or whites, depending on which direction it is.
Two other parameters are essential for the reception of FAX. The first is called drum speed, though obviously nowadays transmission speed would be a better name. It's expressed in lines per minute. The receiving software must sync to this speed, or the pictures will not reproduce properly.
Far, far the most common speed is 120 LPM. It is used for nearly all weather FAX. Some more complex pictures are sent at 60 LPM, a speed which can sound like a time signal.
The second parameter is Index of Cooperation (IOC), expressed as an integer. This is a really arcane thing also dating from the use of drum scanners. It measures the resolution of the FAX. Nobody really has to know what the IOC measures, just what the number is, and it is nearly always 576. On very rare occasion, it's 288. This is way less important for computer screens than it is for rotating drums.
Those who are really curious as to just what the Index of Cooperation is will be pleased to know that it's commonly defined as the product of the total line length and the number of lines per unit length, divided by Pi. It's measuring the ratio of how much distance the scan steps for a new line to the diameter of the drum. The length of time any single FAX can last is determined proportional to the IOC. At 120/576, the standard weather format, this is 18.8 minutes, which is plenty. Going to 60/576 doubles this, along with increasing resolution, though of course the fax takes twice as long to send.
Now it's all clear, right? :-)
Most FAX software allows the setting of black and white or continuous tone (grey scale) modes. Except for satellite weather images, just about every FAX sent on HF nowadays is in black and white. I'll get some argument here, but I've always just kept it on continuous anyway. Otherwise lines get kind of jagged, and typical HF ionospheric multipath fuzz can get grungy looking in a hurry. Plus you have to change it whenever a satellite image is sent, and then change it back again.
Radiofax typically uses a standard called APT (Automatic Picture Transmission). This allows the unattended reception of faxes. Different bands and services use different versions of this, but the one we're interested in is as follows:
5 sec Start Tone (alternate black and white at 300 Hz)
Phasing (30 seconds of white with one black pulse per line)
Image (may have a white interval for sync)
5 sec Stop Tone (alternate black and white at 450 Hz)
Optional 10 sec black
Different agencies have slight variations on this, and these are usually just enough to confuse amateur software. Even so, one will notice that all the information needed to set parameters and receive faxes is here, except maybe for IOC and that's almost always 576 anyway.
Why more computer programs don't take advantage of this is beyond me. They don't however, and so your received fax is usually displaced (left edge is somewhere else in the screen) and slanted (computer is not printing lines at the exact speed of transmission). There are nearly always ways to fix these, either during or after reception.
Slant is way the more annoying of the two, because computer sound cards really aren't up to the task. They don't have the tight frequency tolerance that an expensive dedicated device would have. Typically, the proper slant compensation has to be found manually for a given station, and then it will vary for others, or even change during a long FAX.
I like FAX because it's radio with pictures. One learns how to read the weather charts pretty fast. They're not that different than the ones on the Weather Channel. Also, the satellite images are as good as the ones on your local TV, and better if you get into colorized WEFAX downlinking on higher frequencies.
Many coast guards and weather offices still send hours of these a day, and since they are being used by boats for serious navigation and safety of life at sea, they won't go away any time soon. Check the various lists and radio loggings for something audible in your area.
More from Charles Brain on the Vista Problem
Charles:
Hello Vista users,
I have done a Google search and it seems that the problem is due to the fact that Microsoft have moved the sound drivers from Kernel space to user space. This has caused the hardware acceleration used by some cards to stop working. Accurate information on this problem is very difficult to come by.
It seems the reason that Microsoft did this was to protect Vista from errant sound card drivers not under their control. They were getting fed up with being blamed for crashes that weren't their fault. There are some other reasons for wanting to move the drivers to user space I have been told.
At the moment I can't see any short term fix to this problem as it appears to be outside my control. I understand that this problem is causing a lot of grief among P.C gamers too as they have lost some of their special sound effects.
I am guessing here but what I think is happening is that when I ask for a 48K sample rate the card is returning something else (possibly 44.1K) and that is why it does not work. I base this guess on the fact that I can get PC-HFDL to start on a Vista laptop and display hfdl packets on the spectrum display (indicating the sound handling is working) what it does not do is decode the actual packets (indicating a sample rate problem).
I am sorry I can't be any more helpful/hopeful than that.
- Charles
Thursday, June 19, 2008
Annual VLF Alternator Transmission Coming Up
The Alexanderson Alternator was the first continuous-wave CW transmitter. It is literally a large electric motor-generator that makes RF. A global network of these huge stations was rapidly replacing "King Spark" for maritime coastal radio, when vacuum tubes replaced both.
A working example is at SAQ, Grimeton Radio. RF power is on the order of 200 kW, but the frequency is so low (17.2 kHz, not MHz) as to make it a real catch in North America. From the web site in Sweden:
A working example is at SAQ, Grimeton Radio. RF power is on the order of 200 kW, but the frequency is so low (17.2 kHz, not MHz) as to make it a real catch in North America. From the web site in Sweden:
GRIMETON RADIO/SAQ TRANSMISSION
The annual transmission on "Alexanderson Day" with the Alexanderson alternator on VLF 17.2 kHz will take place Sunday 29th June 2008 at 09:00 UTC (tuning up from after 08:00 UTC) and will be repeated at 13:00 UTC (tuning up from after 12:00 UTC).
The station will be open to visitors.
Amateur Radio Station with special event call "SK6SAQ" will be QRV 09:15 -12:00 UTC on the following frequencies:
- 14.035 kHz CW
- 14.215 kHz SSB
>From 07:00 UTC also on:
- 3.755 kHz SSB.
QSL via SK6DK or direct to address below.
QSL-reports to SAQ and SK6SAQ are kindly received:
- E-mail to: info@alexander.n.se
- or fax to: +46-340-674195
- or via: SM bureau
- or direct by mail to: Alexander - Grimeton Veteranradios Vaenner,
Radiostationen
Grimeton 72
SE-430 16 ROLFSTORP
S W E D E N
Charles Brain: Bad News for PC-ALE Under Vista
From the hflink group on Yahoo:
Hello Folks,
Well I have done yet another Google search to try and find why programs like PC-ALE won't work properly under Vista.
All I can find is that the Microsoft Vista sound development team have completely re-written the Sound subsystem, they have moved it from Kernel space to User space. Apparently the reason they did this was because Microsoft was being blamed for OS crashes by errant sound drivers that were not their fault.
The side effect of this change has been to disable hardware acceleration in a number of soundcards most notably Creative Devices ones. Creative got around the problem by using their version of ALchemy.
I have not tried this but it might help.
Unfortunately this problem with Vista goes places in Windows that I fear to tread so unless some genius comes up with a simple fix Vista support for PC-ALE will never happen. It seems like the only cards that stand a chance of working are the simplest ones with no hardware acceleration.
Looks like my next project will be Linux based!
- Charles
Wednesday, June 11, 2008
Baltops Participating Units
From German Navy:
The multinational Baltic maneuver BALTOPS 2008, a total of 47 international units from 13 different nations.
Dänemark
HDMS OLFERT FISCHER
HDMS VIBEN
HOMEGUARD CUTTERS
RHIBS
EOD TEAM
Deutschland
FGS BAYERN
FGS ELBE
FGS S 72 PUMA
FGS U 15
FGS S 80 HYÄNE
FGS ENSDORF
24 Minen
1x PC-9 Pilatus
1x MPA
2x TORNADO
SubOPauth
MAO C
Estland
BALTRON
Finnland
FNS RAAHE
FNS NAANTALI
Frankreich
FS LOIRE
FS CROIX DE SUD
FS ERIDAN
EOD TEAM
Lettland
LVNS VIESTURS
Litauen
LNS JOTVINGIS
Niederlande
HNLMS MAASLUIS
HNLMS MAKKUM
HNLMS VLAARDINGEN
HNLMS WILLEMSTAD
RNLNA KINGSBERGEN
Polen
ORP GROM
ORP MAMRY
ORP WIGRY
ORP SOKOL
Russland
RFS NEUSTRASHIMY
RFS KALININGRAD
RUS SU-24
RUS SEA BASED HELIX
RUS LAND BASED HELIX
Schweden
HSWMS SKAFTOE
Großbritannien
HMS BULWARK
Vereinigte Staaten von Amerika
USS GETTYSBURG
USS COLE
USNS PATUXENT
1x MPA
NATO Baltops Exercise Under Way
5102.5 lit up with US and German participating units. Norwegian navy also heard. Expect tactical comm on many European frequencies. NUKO formatting and unit calling NAA. Sounds like old times.
Friday, June 06, 2008
Digital Mode of the Week: PSK31 (Part 2 - Phase-Shift Keying)
PSK31 was developed in 1998 by Peter Martinez, a British ham with the call G3PLX. It was intended to improve on RTTY for the purpose of direct, keyboard-to-keyboard contacts and rag chews. PSK stands for Phase-Shift Keying, and 31 refers to the baud rate of 31.25. This sounds slow, but it is perfect for hand typing, and it was also easy to count down from the 8000-Hz sample rate common for sound cards of the era.
Unlike many digital modes, which continued to be somewhat esoteric for ham use, PSK31 caught on immediately. From very early on, it was extremely well suited for generating and decoding with user-friendly, sound card software on ordinary personal computers. In use, the mode proved to be very efficient in its use of power and spectrum, allowing hams to communicate on HF without the equipment taking over their lives (and pocketbooks).
Right now, one can tune to 14070 kHz any time the band is open and find multiple signals all warbling away. Often it sounds like an attack from extraterrestrial science fiction insects. Less active frequencies are 10138-40 and 7035.
While PSK31 can have different modulation schemes, the one most commonly used is Binary Phase-Shift Keying (BPSK). Data is transmitted by commanding the sound card to shift the phase of the baseband audio signal by 180 degrees, in effect inverting the polarity.
Ordinarily, this would create a tremendous key click, but the amplitude is synchronously shaped by cosine modulation at the same time. The result is a best-case bandwidth for a PROPERLY MODULATED signal that is theoretically equal to the baud rate - yes, 31.25 hertz!! That is narrower than "hard" on-off keyed CW at a comparable 50 WPM.
Of course, things in the real world are somewhat more complicated. As can be easily seen on the waterfall, many signals have varying amounts of clicking or IM audio distortion, and they are maybe 40 or 50 Hz wide. This gets worse if the operator is hitting it too hard and causing more sidebands to appear. For the most part, though, PSK31 is one of the narrowest modes ever designed for hams.
The narrow bandwidth and low data rate make PSK31 practically immune to selective ionospheric fading (that Moog whooshing sound you hear on wider modes like HFDL and STANAG 4285). It performs less well under phase and Doppler distortion such as from aurora.
In this keying system, any phase flip signals a 0 bit. If there's no shift at the right time, it's a one bit. As we've seen, the state doesn't matter, it's the change in state. Again, it can be tuned in USB or LSB, though USB is traditional.
A character space is two zeroes - 00. This is why all the characters end in 1.
The PSK31 idler consists of all zeroes, which flip the phase at the baud rate. This and the cosine shaping produce what is basically double-sideband suppressed-carrier emission (J2B). ITU refers to it as 60H0J2B, in the long international designators. This means suppressed-carrier modulation for automatic reception using a maximum channel width of 60 hertz.
The transmission starts with a distinctive railroad track pattern on the waterfall. Bursts of hand typing create something looking more like a DNA molecule. At the end of the transmission, it all collapses back into the single tone.
Receiving consists of syncing to the baud rate, which is determined from the signal, and sending the resulting data to a Viterbi decoder. There are no connections, and no error checks. Stations take turns sending, just like RTTY. Character hits print gibberish, again like RTTY. However, the copy is usually much better on HF, everything else being equal.
There's not much else to know. BPSK31 is very uncomplicated to the user. You click on a signal and copy comes out.
PSK31 immediately gave rise to a bewildering array of phase-shift keyed, character-based, half-duplex modes. If you've used MultiPSK you know what I'm talking about. Each new version has more little buttons and more funny noises than the last one. Since decode sync is determined from the signal, there's also an autodetect mode.
An early variant that should be in just about all PSK31 software is QPSK31. This stands for quaternary phase-shift keying. On the standard computer phase constellation display, you will see four points instead of two. This is done through the use of a second BPSK carrier shifted 90 degrees (in quadrature), driving a second receive demodulator.
While this should double throughput, the extra capacity is used for an error check and more robust decoding. The performance of this mode on degraded circuits is impressive, but at the cost of more bandwidth and a tuning precision challenging even modern solid-state radios.
Other BPSK and QPSK modes are at 10, 63, 125, and 250 baud. There's also PSK220F, a 220-baud mode well adapted to broadcasting. It is used by the Cuban numbers operation at times.
Unlike many digital modes, which continued to be somewhat esoteric for ham use, PSK31 caught on immediately. From very early on, it was extremely well suited for generating and decoding with user-friendly, sound card software on ordinary personal computers. In use, the mode proved to be very efficient in its use of power and spectrum, allowing hams to communicate on HF without the equipment taking over their lives (and pocketbooks).
Right now, one can tune to 14070 kHz any time the band is open and find multiple signals all warbling away. Often it sounds like an attack from extraterrestrial science fiction insects. Less active frequencies are 10138-40 and 7035.
While PSK31 can have different modulation schemes, the one most commonly used is Binary Phase-Shift Keying (BPSK). Data is transmitted by commanding the sound card to shift the phase of the baseband audio signal by 180 degrees, in effect inverting the polarity.
Ordinarily, this would create a tremendous key click, but the amplitude is synchronously shaped by cosine modulation at the same time. The result is a best-case bandwidth for a PROPERLY MODULATED signal that is theoretically equal to the baud rate - yes, 31.25 hertz!! That is narrower than "hard" on-off keyed CW at a comparable 50 WPM.
Of course, things in the real world are somewhat more complicated. As can be easily seen on the waterfall, many signals have varying amounts of clicking or IM audio distortion, and they are maybe 40 or 50 Hz wide. This gets worse if the operator is hitting it too hard and causing more sidebands to appear. For the most part, though, PSK31 is one of the narrowest modes ever designed for hams.
The narrow bandwidth and low data rate make PSK31 practically immune to selective ionospheric fading (that Moog whooshing sound you hear on wider modes like HFDL and STANAG 4285). It performs less well under phase and Doppler distortion such as from aurora.
In this keying system, any phase flip signals a 0 bit. If there's no shift at the right time, it's a one bit. As we've seen, the state doesn't matter, it's the change in state. Again, it can be tuned in USB or LSB, though USB is traditional.
A character space is two zeroes - 00. This is why all the characters end in 1.
The PSK31 idler consists of all zeroes, which flip the phase at the baud rate. This and the cosine shaping produce what is basically double-sideband suppressed-carrier emission (J2B). ITU refers to it as 60H0J2B, in the long international designators. This means suppressed-carrier modulation for automatic reception using a maximum channel width of 60 hertz.
The transmission starts with a distinctive railroad track pattern on the waterfall. Bursts of hand typing create something looking more like a DNA molecule. At the end of the transmission, it all collapses back into the single tone.
Receiving consists of syncing to the baud rate, which is determined from the signal, and sending the resulting data to a Viterbi decoder. There are no connections, and no error checks. Stations take turns sending, just like RTTY. Character hits print gibberish, again like RTTY. However, the copy is usually much better on HF, everything else being equal.
There's not much else to know. BPSK31 is very uncomplicated to the user. You click on a signal and copy comes out.
PSK31 immediately gave rise to a bewildering array of phase-shift keyed, character-based, half-duplex modes. If you've used MultiPSK you know what I'm talking about. Each new version has more little buttons and more funny noises than the last one. Since decode sync is determined from the signal, there's also an autodetect mode.
An early variant that should be in just about all PSK31 software is QPSK31. This stands for quaternary phase-shift keying. On the standard computer phase constellation display, you will see four points instead of two. This is done through the use of a second BPSK carrier shifted 90 degrees (in quadrature), driving a second receive demodulator.
While this should double throughput, the extra capacity is used for an error check and more robust decoding. The performance of this mode on degraded circuits is impressive, but at the cost of more bandwidth and a tuning precision challenging even modern solid-state radios.
Other BPSK and QPSK modes are at 10, 63, 125, and 250 baud. There's also PSK220F, a 220-baud mode well adapted to broadcasting. It is used by the Cuban numbers operation at times.
Saturday, May 31, 2008
Digital Mode of the Week: PSK31 (Part 1 - Varicode)
Varicode is a Huffman code for use in PSK31 narrow band teleprinting. PSK31 is a binary phase-shift keyed, 31.35-baud mode designed for direct keyboard-to-keyboard ham contacts. Varicode is integral to the overall concept that made PSK31 so well suited to ham radio, despite this low baud rate. In fact, it was the original name for the whole mode that was proposed in 1998 by its developer, an English ham named Peter Martinez (G3PLX).
Like many "major breakthroughs" in radio, the underlying concept has actually been around a while - in this case, since the Morse code. Morse speeds up transmission by making the more commonly used characters shorter, for example a single dit for E. Morse, like Huffman coding, lends itself to tree-shaped decoding algorithms that save a lot of time. Unlike with Baudot, logic can be designed (including in your brain) that bails out of the loop whenever it detects that a character is complete.
The basic Varicode character set is the same as 7-bit ASCII, but the bits aren't, and the framing is completely different. Throughput is a lot faster than if straight ASCII were being sent and everything else was equal. One consideration, however, is that efficiency goes down in languages other than English, or if the traffic is something other than plain lower case text. Either situation begins to deviate from the designed optimum.
The shortest character is the blank space (a single 1 bit), and second shortest is the lower case e (11). Note that all characters, including nulls, end in a 1. This is due to the technical characteristics of the transmission mode, which we'll talk about next week.
Here's the code. It should look familiar, except for the bits.
Dec . Hex .. Char ... Bit Code
....0 ... 00 ... NUL ... 1010101011
....1 ... 01 ... SOH ... 1011011011
....2 ... 02 ... STX ... 1011101101
....3 ... 03 ... ETX ... 1101110111
....4 ... 04 ... EOT ... 1011101011
....5 ... 05 ... ENQ ... 1101011111
....6 ... 06 ... ACK ... 1011101111
....7 ... 07 ... BEL .... 1011111101
....8 ... 08 ... BS ...... 1011111111
....9 ... 09 ... HT ...... 11101111
..10 ... 0A ... LF ...... 11101
..11 ... 0B ... VT ..... 1101101111
..12 ... 0C ... FF ...... 1011011101
..13 ... 0D ... CR ..... 11111
..14 ... 0E ... SO ...... 1101110101
..15 ... 0F ... SI ....... 1110101011
..16 ... 10 ... DLE ... 1011110111
..17 ... 11 ... DC1 ... 1011110101
..18 ... 12 ... DC2 ... 1110101101
..19 ... 13 ... DC3 ... 1110101111
..20 ... 14 ... DC4 ... 1101011011
..21 ... 15 ... NAK .. 1101101011
..22 ... 16 ... SYN ... 1101101101
..23 ... 17 ... ETB ... 1101010111
..24 ... 18 ... CAN .. 1101111011
..25 ... 19 ... EM ..... 1101111101
..26 ... 1A ... SUB .. 1110110111
..27 ... 1B ... ESC ... 1101010101
..28 ... 1C ... FS ..... 1101011101
..29 ... 1D ... GS .... 1110111011
..30 ... 1E ... RS ..... 1011111011
..31 ... 1F ... US ..... 1101111111
..32 ... 20 ... SP....... 1
..33 ... 21 ... ! ..... 111111111
..34 ... 22 ... " ..... 101011111
..35 ... 23 ... # .... 111110101
..36 ... 24 ... $ .... 111011011
..37 ... 25 ... % ... 1011010101
..38 ... 26 ... & .. 1010111011
..39 ... 27 ... ' ..... 101111111
..40 ... 28 ... ( .... 11111011
..41 ... 29 ... ) .... 11110111
..42 ... 2A ... * .. 101101111
..43 ... 2B ... +... 111011111
..44 ... 2C ... , .. 1110101
..45 ... 2D ... - .. 110101
..46 ... 2E ... . .. 1010111
..47 ... 2F ... / .. 110101111
..48 ... 30 ... 0... 10110111
..49 ... 31 ... 1... 10111101
..50 ... 32 ... 2... 11101101
..51 ... 33 ... 3... 11111111
..52 ... 34 ... 4... 101110111
..53 ... 35 ... 5... 101011011
..54 ... 36 ... 6... 101101011
..55 ... 37 ... 7... 110101101
..56 ... 38 ... 8... 110101011
..57 ... 39 ... 9... 110110111
..58 ... 3A ... : .. 11110101
..59 ... 3B ... ; .. 110111101
..60 ... 3C ... < .. 111101101
..61 ... 3D ... = .. 1010101
..62 ... 3E ... > .. 111010111
..63 ... 3F ... ? .. 1010101111
..64 ... 40 ... @ .. 1010111101
..65 ... 41 ... A... 1111101
..66 ... 42 ... B... 11101011
..67 ... 43 ... C... 10101101
..68 ... 44 ... D... 10110101
..69 ... 45 ... E... 1110111
..70 ... 46 ... F... 11011011
..71 ... 47 ... G... 11111101
..72 ... 48 ... H... 101010101
..73 ... 49 ... I... 1111111
..74 ... 4A ... J... 111111101
..75 ... 4B ... K... 101111101
..76 ... 4C ... L... 11010111
..77 ... 4D ... M... 10111011
..78 ... 4E ... N... 11011101
..79 ... 4F ... O... 10101011
..80 ... 50 ... P... 11010101
..81 ... 51 ... Q... 1111011101
..82 ... 52 ... R... 10101111
..83 ... 53 ... S... 1101111
..84 ... 54 ... T... 1101101
..85 ... 55 ... U... 101010111
..86 ... 56 ... V... 110110101
..87 ... 57 ... W... 101011101
..88 ... 58 ... X... 101110101
..89 ... 59 ... Y... 101111011
..90 ... 5A ... Z... 1010101101
..91 ... 5B ... [ .. 111110111
..92 ... 5C ... \ .. 111101111
..93 ... 5D ... ]... 111111011
..94 ... 5E ... ^ .. 1010111111
..95 ... 5F ... _ .. 101101101
..96 ... 60 ... ` .. 1011011111
..97 ... 61 ... a..... 1011
..98 ... 62 ... b..... 1011111
..99 ... 63 ... c..... 101111
100 ... 64 ... d..... 101101
101 ... 65 ... e..... 11
102 ... 66 ... f..... 111101
103 ... 67 ... g..... 1011011
104 ... 68 ... h..... 101011
105 ... 69 ... i...... 1101
106 ... 6A ... j..... 111101011
107 ... 6B ... k..... 10111111
108 ... 6C ... l..... 11011
109 ... 6D ... m... 111011
110 ... 6E ... n.... 1111
111 ... 6F ... o..... 111
112 ... 70 ... p..... 111111
113 ... 71 ... q..... 110111111
114 ... 72 ... r..... 10101
115 ... 73 ... s..... 10111
116 ... 74 ... t..... 101
117 ... 75 ... u..... 110111
118 ... 76 ... v..... 1111011
119 ... 77 ... w..... 1101011
120 ... 78 ... x..... 11011111
121 ... 79 ... y..... 1011101
122 ... 7A ... z..... 111010101
123 ... 7B ... {..... 1010110111
124 ... 7C ... |..... 110111011
125 ... 7D ... }.... 1010110101
126 ... 7E ... ~..... 1011010111
127 ... 7F .. DEL ... 1110110101
Like many "major breakthroughs" in radio, the underlying concept has actually been around a while - in this case, since the Morse code. Morse speeds up transmission by making the more commonly used characters shorter, for example a single dit for E. Morse, like Huffman coding, lends itself to tree-shaped decoding algorithms that save a lot of time. Unlike with Baudot, logic can be designed (including in your brain) that bails out of the loop whenever it detects that a character is complete.
The basic Varicode character set is the same as 7-bit ASCII, but the bits aren't, and the framing is completely different. Throughput is a lot faster than if straight ASCII were being sent and everything else was equal. One consideration, however, is that efficiency goes down in languages other than English, or if the traffic is something other than plain lower case text. Either situation begins to deviate from the designed optimum.
The shortest character is the blank space (a single 1 bit), and second shortest is the lower case e (11). Note that all characters, including nulls, end in a 1. This is due to the technical characteristics of the transmission mode, which we'll talk about next week.
Here's the code. It should look familiar, except for the bits.
Dec . Hex .. Char ... Bit Code
....0 ... 00 ... NUL ... 1010101011
....1 ... 01 ... SOH ... 1011011011
....2 ... 02 ... STX ... 1011101101
....3 ... 03 ... ETX ... 1101110111
....4 ... 04 ... EOT ... 1011101011
....5 ... 05 ... ENQ ... 1101011111
....6 ... 06 ... ACK ... 1011101111
....7 ... 07 ... BEL .... 1011111101
....8 ... 08 ... BS ...... 1011111111
....9 ... 09 ... HT ...... 11101111
..10 ... 0A ... LF ...... 11101
..11 ... 0B ... VT ..... 1101101111
..12 ... 0C ... FF ...... 1011011101
..13 ... 0D ... CR ..... 11111
..14 ... 0E ... SO ...... 1101110101
..15 ... 0F ... SI ....... 1110101011
..16 ... 10 ... DLE ... 1011110111
..17 ... 11 ... DC1 ... 1011110101
..18 ... 12 ... DC2 ... 1110101101
..19 ... 13 ... DC3 ... 1110101111
..20 ... 14 ... DC4 ... 1101011011
..21 ... 15 ... NAK .. 1101101011
..22 ... 16 ... SYN ... 1101101101
..23 ... 17 ... ETB ... 1101010111
..24 ... 18 ... CAN .. 1101111011
..25 ... 19 ... EM ..... 1101111101
..26 ... 1A ... SUB .. 1110110111
..27 ... 1B ... ESC ... 1101010101
..28 ... 1C ... FS ..... 1101011101
..29 ... 1D ... GS .... 1110111011
..30 ... 1E ... RS ..... 1011111011
..31 ... 1F ... US ..... 1101111111
..32 ... 20 ... SP....... 1
..33 ... 21 ... ! ..... 111111111
..34 ... 22 ... " ..... 101011111
..35 ... 23 ... # .... 111110101
..36 ... 24 ... $ .... 111011011
..37 ... 25 ... % ... 1011010101
..38 ... 26 ... & .. 1010111011
..39 ... 27 ... ' ..... 101111111
..40 ... 28 ... ( .... 11111011
..41 ... 29 ... ) .... 11110111
..42 ... 2A ... * .. 101101111
..43 ... 2B ... +... 111011111
..44 ... 2C ... , .. 1110101
..45 ... 2D ... - .. 110101
..46 ... 2E ... . .. 1010111
..47 ... 2F ... / .. 110101111
..48 ... 30 ... 0... 10110111
..49 ... 31 ... 1... 10111101
..50 ... 32 ... 2... 11101101
..51 ... 33 ... 3... 11111111
..52 ... 34 ... 4... 101110111
..53 ... 35 ... 5... 101011011
..54 ... 36 ... 6... 101101011
..55 ... 37 ... 7... 110101101
..56 ... 38 ... 8... 110101011
..57 ... 39 ... 9... 110110111
..58 ... 3A ... : .. 11110101
..59 ... 3B ... ; .. 110111101
..60 ... 3C ... < .. 111101101
..61 ... 3D ... = .. 1010101
..62 ... 3E ... > .. 111010111
..63 ... 3F ... ? .. 1010101111
..64 ... 40 ... @ .. 1010111101
..65 ... 41 ... A... 1111101
..66 ... 42 ... B... 11101011
..67 ... 43 ... C... 10101101
..68 ... 44 ... D... 10110101
..69 ... 45 ... E... 1110111
..70 ... 46 ... F... 11011011
..71 ... 47 ... G... 11111101
..72 ... 48 ... H... 101010101
..73 ... 49 ... I... 1111111
..74 ... 4A ... J... 111111101
..75 ... 4B ... K... 101111101
..76 ... 4C ... L... 11010111
..77 ... 4D ... M... 10111011
..78 ... 4E ... N... 11011101
..79 ... 4F ... O... 10101011
..80 ... 50 ... P... 11010101
..81 ... 51 ... Q... 1111011101
..82 ... 52 ... R... 10101111
..83 ... 53 ... S... 1101111
..84 ... 54 ... T... 1101101
..85 ... 55 ... U... 101010111
..86 ... 56 ... V... 110110101
..87 ... 57 ... W... 101011101
..88 ... 58 ... X... 101110101
..89 ... 59 ... Y... 101111011
..90 ... 5A ... Z... 1010101101
..91 ... 5B ... [ .. 111110111
..92 ... 5C ... \ .. 111101111
..93 ... 5D ... ]... 111111011
..94 ... 5E ... ^ .. 1010111111
..95 ... 5F ... _ .. 101101101
..96 ... 60 ... ` .. 1011011111
..97 ... 61 ... a..... 1011
..98 ... 62 ... b..... 1011111
..99 ... 63 ... c..... 101111
100 ... 64 ... d..... 101101
101 ... 65 ... e..... 11
102 ... 66 ... f..... 111101
103 ... 67 ... g..... 1011011
104 ... 68 ... h..... 101011
105 ... 69 ... i...... 1101
106 ... 6A ... j..... 111101011
107 ... 6B ... k..... 10111111
108 ... 6C ... l..... 11011
109 ... 6D ... m... 111011
110 ... 6E ... n.... 1111
111 ... 6F ... o..... 111
112 ... 70 ... p..... 111111
113 ... 71 ... q..... 110111111
114 ... 72 ... r..... 10101
115 ... 73 ... s..... 10111
116 ... 74 ... t..... 101
117 ... 75 ... u..... 110111
118 ... 76 ... v..... 1111011
119 ... 77 ... w..... 1101011
120 ... 78 ... x..... 11011111
121 ... 79 ... y..... 1011101
122 ... 7A ... z..... 111010101
123 ... 7B ... {..... 1010110111
124 ... 7C ... |..... 110111011
125 ... 7D ... }.... 1010110101
126 ... 7E ... ~..... 1011010111
127 ... 7F .. DEL ... 1110110101
STS-124 Countdown Continues
Launch is still scheduled for around 2104 UTC today (Saturday). The astronauts are presently entering the spacecraft.
Allan Stern has heard Booster Recovery Vessel traffic on 10780 and 5711 kHz.
Allan Stern has heard Booster Recovery Vessel traffic on 10780 and 5711 kHz.
Wednesday, May 28, 2008
STS-124 Tentative Launch Is Saturday
Shuttle Discovery's STS-124 mission to the International Space Station is scheduled to lift off at 5:02 p.m. EDT [2102 UTC] on Saturday, May 31.
Astronauts arrived at KSC this morning.
NASA will provide continuous online updates, including a webcast and a blog on the STS-124 mission at:
http://www.nasa.gov/shuttle
On launch day, a blog will update the countdown beginning at noon. Originating from NASA's Kennedy Space Center, the blog is the definitive Internet source for information leading up to launch. During the mission, visitors to NASA's shuttle Web site can read about the crew's progress and watch the spacewalks live. As Discovery's flight wraps up, NASA will offer a blog detailing the spacecraft's return to Earth.
Detailed lists of countdown milestones, news briefing times and participants, and hours of operation for Kennedy's news center and media credentialing office are available at:
http://www.nasa.gov/mission_pages/shuttle/news
For NASA TV streaming video, scheduling and downlink information, visit:
http://www.nasa.gov/ntv
Astronauts arrived at KSC this morning.
NASA will provide continuous online updates, including a webcast and a blog on the STS-124 mission at:
http://www.nasa.gov/shuttle
On launch day, a blog will update the countdown beginning at noon. Originating from NASA's Kennedy Space Center, the blog is the definitive Internet source for information leading up to launch. During the mission, visitors to NASA's shuttle Web site can read about the crew's progress and watch the spacewalks live. As Discovery's flight wraps up, NASA will offer a blog detailing the spacecraft's return to Earth.
Detailed lists of countdown milestones, news briefing times and participants, and hours of operation for Kennedy's news center and media credentialing office are available at:
http://www.nasa.gov/mission_pages/shuttle/news
For NASA TV streaming video, scheduling and downlink information, visit:
http://www.nasa.gov/ntv
Sunday, May 25, 2008
Digital Mode of the Week: HFDL
HFDL stands for High-Frequency Data Link. It is the HF band portion of a comprehensive, global, air-ground, communications system that also uses VHF and satellite. The ACARS ( Aircraft Communications Addressing and Reporting System) is another part of all this. Most people associate ACARS with VHF, but the HFDL protocol can carry it as well.
The HFDL standard is ARINC Report 635-3 (HF Data Link Protocols), which can be ordered from the company, Aeronautical Radio Inc, for a price. ARINC is a private company, formerly owned by the airlines, but now contracting with them for communication services.
Like packet radio, HFDL has layers. These are physical, link, and subnetwork. The subnetwork layer isn't important for receiving, since we're just randomly decoding everything on a frequency.
The physical layer is, once again, the actual transmission of data over the radio. HFDL is a single-tone, phase-shift keyed, text-based, error-checking mode with a baseband audio carrier frequency of 1440 Hz. It is tuned in USB, and the 1440 Hz center is critical for decoding. LSB works too, but the dial frequencies won't match the ones in the ARINC database.
Each burst begins with the unmodulated 1440-Hz tone, so that the decoder's automatic frequency control can lock on. This is the scary-sounding "frequency error" that is output by the decoder. Errors within 50 Hz or so can be ignored. This beeping, followed by hiss, is what the mode sounds like.
The symbol speed is fixed at 1800 baud, but the data rate is determined by the exact modulation used. BPSK is 300 bps, QPSK is 600, and 8PSK is 1200 or 1800. 300 is by far the most common, though I've heard it go up to 1200. Tuning error, modulation type, and signal quality are best viewed on a phase constellation display like the one in the PC-HFDL program.
Frequencies are stored in a numbered database, called a system table, which is sent by ARINC to all stations. A few times a year, the table is replaced by a new one with a higher number. The resulting mismatch causes aircraft software to request an update, which we receive too. At least one decoding program (again PC-HFDL) will grab these for its own use, if you're lucky to hear one. Afterward, the frequencies show up in kHz, which is extremely convenient. Otherwise, there are ways to update PC-HFDL manually with system tables found online.
Old databases aren't useless. The frequencies always come from the same pool, and never change that much.
Ground stations pick 2-3 frequencies from the table depending on propagation. This may change every few hours. The frequencies being used by the entire network are sent, two stations at a time, in the "squitter." (Squitter in air comm jargon is an unsolicited information transmission. More on these soon.)
Aircraft can choose frequencies, or even ground stations. If reception exists, they can also switch to satellite or VHF. The comm status is passed to the ground station. All this is automatic, so the crew can just get on with flying the airplane.
Transmission types are uplinks (ground-air), downlinks (air-ground), and the aforementioned squitters. A squitter is always sent every 32 seconds by the ground. It contains various network maintenance data, including all the frequencies (if you wait long enough). It's also a quick propagation check, because you're never more than half a minute from a ground transmission coming from a known location. Of course, aircraft may be heard even if the squitters are inaudible, and vice versa.
HFDL uses a simple form of time-division multiplex. The entire 32-second cycle is divided into 13 numbered slots of 2.5 seconds each. Slot 0 is always the squitter, leaving 1-12 for up- and downlinks. Databursts always occupy all of one slot, though the various overheads of the physical layer reduce the actual transmission of data to 1.8 seconds. Sometimes an uplink with an embedded ACARS message might require a double-length transmission using two slots.
The network assigns the use of these slots, keeping stations from transmitting at once. Assignments are made by ID, a temporary hexadecimal number given each aircraft at logon.
The use of condensed message formats and lookup tables makes HFDL extremely efficient in its use of air time. It's amazing how much can be crammed into a 2-second burst. Most decoders have a "verbose" mode which will output everything. Hundreds of lines with every kind of count and measurement you can think of will scroll madly up your screen, filling your buffer at a merry rate.
Really long ACARS messages, like airport arrival information (ATIS), can be sent in numbered packets (same as on VHF). Otherwise the communication makes use of standard formatted blocks called Protocol Data Units (PDU). This gets geeky in a hurry. Rather than write a 2000-word blog entry, I'll just list them:
SPDU
Squitter Protocol Data Unit
Frequencies and slot assignments, plus network maintenance data
PDU (PREAM)
Preamble Data Unit
Basic negotiation of connection - frequency error, station ID, bit rate, etc
BDU
Basic Data Unit
The smallest data block, from which LPDU are built
LPDU
Link Protocol Data Unit
Larger structure, which in turn makes up the largest ones
MPDU
Media Access Protocol Data Unit
Several LPDU concerning login, aircraft ID, and the ACARS message, if any
HFNPDU
High-Frequency Network Protocol Data Unit
Several LPDU, containing all manner of data, most for network maintenance. The most useful to us is HFNPDU PERFORMANCE, which will usually contain the flight number and GPS position of the aircraft.
Here are the ARINC ground stations. Note that some numbers are skipped:
1 San Francisco, CA
2 Molokai, HI
3 Reykjavik, Iceland
4 New York, NY
5 Auckland, NZ
6 Hat Yai, Thailand
7 Shannon, Ireland
8 Johannesburg, S. Africa
9 Barrow, AK
13 Santa Cruz, Bolivia
14 Krasnoyarsk, Russia
15 Al Muharraq, Bahrain
16 Guam
17 Canarias (Canary Islands)
The HFDL standard is ARINC Report 635-3 (HF Data Link Protocols), which can be ordered from the company, Aeronautical Radio Inc, for a price. ARINC is a private company, formerly owned by the airlines, but now contracting with them for communication services.
Like packet radio, HFDL has layers. These are physical, link, and subnetwork. The subnetwork layer isn't important for receiving, since we're just randomly decoding everything on a frequency.
The physical layer is, once again, the actual transmission of data over the radio. HFDL is a single-tone, phase-shift keyed, text-based, error-checking mode with a baseband audio carrier frequency of 1440 Hz. It is tuned in USB, and the 1440 Hz center is critical for decoding. LSB works too, but the dial frequencies won't match the ones in the ARINC database.
Each burst begins with the unmodulated 1440-Hz tone, so that the decoder's automatic frequency control can lock on. This is the scary-sounding "frequency error" that is output by the decoder. Errors within 50 Hz or so can be ignored. This beeping, followed by hiss, is what the mode sounds like.
The symbol speed is fixed at 1800 baud, but the data rate is determined by the exact modulation used. BPSK is 300 bps, QPSK is 600, and 8PSK is 1200 or 1800. 300 is by far the most common, though I've heard it go up to 1200. Tuning error, modulation type, and signal quality are best viewed on a phase constellation display like the one in the PC-HFDL program.
Frequencies are stored in a numbered database, called a system table, which is sent by ARINC to all stations. A few times a year, the table is replaced by a new one with a higher number. The resulting mismatch causes aircraft software to request an update, which we receive too. At least one decoding program (again PC-HFDL) will grab these for its own use, if you're lucky to hear one. Afterward, the frequencies show up in kHz, which is extremely convenient. Otherwise, there are ways to update PC-HFDL manually with system tables found online.
Old databases aren't useless. The frequencies always come from the same pool, and never change that much.
Ground stations pick 2-3 frequencies from the table depending on propagation. This may change every few hours. The frequencies being used by the entire network are sent, two stations at a time, in the "squitter." (Squitter in air comm jargon is an unsolicited information transmission. More on these soon.)
Aircraft can choose frequencies, or even ground stations. If reception exists, they can also switch to satellite or VHF. The comm status is passed to the ground station. All this is automatic, so the crew can just get on with flying the airplane.
Transmission types are uplinks (ground-air), downlinks (air-ground), and the aforementioned squitters. A squitter is always sent every 32 seconds by the ground. It contains various network maintenance data, including all the frequencies (if you wait long enough). It's also a quick propagation check, because you're never more than half a minute from a ground transmission coming from a known location. Of course, aircraft may be heard even if the squitters are inaudible, and vice versa.
HFDL uses a simple form of time-division multiplex. The entire 32-second cycle is divided into 13 numbered slots of 2.5 seconds each. Slot 0 is always the squitter, leaving 1-12 for up- and downlinks. Databursts always occupy all of one slot, though the various overheads of the physical layer reduce the actual transmission of data to 1.8 seconds. Sometimes an uplink with an embedded ACARS message might require a double-length transmission using two slots.
The network assigns the use of these slots, keeping stations from transmitting at once. Assignments are made by ID, a temporary hexadecimal number given each aircraft at logon.
The use of condensed message formats and lookup tables makes HFDL extremely efficient in its use of air time. It's amazing how much can be crammed into a 2-second burst. Most decoders have a "verbose" mode which will output everything. Hundreds of lines with every kind of count and measurement you can think of will scroll madly up your screen, filling your buffer at a merry rate.
Really long ACARS messages, like airport arrival information (ATIS), can be sent in numbered packets (same as on VHF). Otherwise the communication makes use of standard formatted blocks called Protocol Data Units (PDU). This gets geeky in a hurry. Rather than write a 2000-word blog entry, I'll just list them:
SPDU
Squitter Protocol Data Unit
Frequencies and slot assignments, plus network maintenance data
PDU (PREAM)
Preamble Data Unit
Basic negotiation of connection - frequency error, station ID, bit rate, etc
BDU
Basic Data Unit
The smallest data block, from which LPDU are built
LPDU
Link Protocol Data Unit
Larger structure, which in turn makes up the largest ones
MPDU
Media Access Protocol Data Unit
Several LPDU concerning login, aircraft ID, and the ACARS message, if any
HFNPDU
High-Frequency Network Protocol Data Unit
Several LPDU, containing all manner of data, most for network maintenance. The most useful to us is HFNPDU PERFORMANCE, which will usually contain the flight number and GPS position of the aircraft.
Here are the ARINC ground stations. Note that some numbers are skipped:
1 San Francisco, CA
2 Molokai, HI
3 Reykjavik, Iceland
4 New York, NY
5 Auckland, NZ
6 Hat Yai, Thailand
7 Shannon, Ireland
8 Johannesburg, S. Africa
9 Barrow, AK
13 Santa Cruz, Bolivia
14 Krasnoyarsk, Russia
15 Al Muharraq, Bahrain
16 Guam
17 Canarias (Canary Islands)
Saturday, May 24, 2008
Interesting RTTY Message from KSM 24 May 08
KSM is the commercial station at the Maritime Radio Historical Society, Pt. Reyes, CA (at the old RCA/MCI maritime and point to point site). In cooperation with the Comm Center group on Yahoo!, which is comprised of former or retired military communicators, it broadcast several RTTY/RATT messages in standard military form.
Here's one of the most interesting ones. All net discipline is exactly as received. The "?" character was used in the message to replace ones that aren't in ITA2. Any format changes, such as stripping leading blanks, were done by Blogger, not me:
VV HNA033
RR RUWMKSM
DE RUMLNHA 0033 1410200
ZNR UUUUU
R 200131Z MAY 08
FM COMMCENTER AT YAHOOGROUPS.COM //NNN7DXB//
TO KSM MARINE RADIO SAN FRANCISCO CA //KSM BCST//
BT
UNCLAS
SUBJ: ACP-127 FORMATTED MESSAGE
REF: ACP-127 TAPE RELAY INSTRUCTIONS ( )
1. THIS IS AN EXAMPLE OF A MILITARY MESSAGE FORMATTED IN
THE ACP-127 TELETYPE TAPE RELAY FORMAT THAT WAS IN USE
IN THE US MILITARY PRIOR TO THE MID-1970S. DURING THE 1970S,
THE MILITARY TELETYPE TAPE RELAY SYSTEM, ALSO KNOWN AS
THE ?TORN TAPE RELAY SYSTEM? WAS SLOWLY REPLACED BY THE NEWER
AND FASTER AUTOMATIC DIGITIAL NETWORK, OR ?AUTODIN?.
2. AUTODIN WAS A HIGH-SPEED, HIGH CAPACITY, COMPUTER CONTROLLED
?SUPER TELETYPE? SYSTEM THAT WAS ALSO CAPABLE OF HANDLING
DATA TRAFFIC IN IBM PUNCHED CARD FORM (HOLLERITH CODE), AND
MAGNETIC MEDIA. IT RELIED ON SERVOS AND TAPE DRIVES, AND LATER,
WAS UPGRADED WITH WHAT WE NOW REFER TO AS HARD DRIVES
THAT WERE ABOUT THE SIZE OF WASHING MACHINES. SOME OF
THE MAIN BRAINS IN THE AUTODIN SYSTEM WERE RCA SPECTRE 70
PAGE 2 RUMLNHA0033 UNCLAS
MAIN FRAME COMPUTERS. MOST ARMY AUTODIN FACILITIES WERE
MAINTAINED BY EITHER PHILCO-FORD OR WESTERN UNION UNDER
DOD CONTRACT. AUTODIN ITSELF WAS FINALLY REPLACED ON
SEPTEMBER 30, 2003 BY A NEW MEDIUM CALLED THE DEFENSE
MESSAGING SYSTEM, OR ?DMS?. DMS OFFERS MORE CAPACITY THAN
DID AUTODIN. IT PERMITS ATTACHMENTS, GRAPHICS, MAPS, MAP
OVERLAYS, LETTERS AND NON-MESSAGE CORRESPONDENCE, FILES,
AND EMAIL TRAFFIC TO BE TRANSMITTED IN A SINGLE SECURE SYSTEM
THAT IS WORLDWIDE IN SCOPE AND OPERATION.
3. ACP-127 PROCEDURES HOWEVER, DIDN"T GO AWAY. MOST US
MILITARY TACTICAL CIRCUITS STILL USED ACP-127 FORMATS UNTIL
THE LATE 1980S, UNTIL THE AUTODIN SYSTEM WAS FINALLY
INTEGRATED IN THE FIELD UNITS. NATO UNITS CONTINUED TO USE
ACP-127 FORMATS, SINCE NONE OF THEIR EQUIPMENTS OR SYSTEMS
WERE COMPATIBLE WITH THE US COMPUTERIZED FORMAT. SYSTEM
COMPATIBILITY IN THOSE DAYS WAS CALLED ?INTEROPERABILITY?.
EVEN TODAY, ACP-127 FORMATS CAN STILL BE FOUND IN SOME
NATO COUNTRIES WHERE INTEROPERABILITY ISSUES CONTINUE
TO PERSIST.
4. TRANSMITTED AS AN INFORMATIONAL SERVICE BY THE
PAGE 3 RUMLNHA0033 UNCLAS
COMMCENTER AT YAHOOGROUPS.COM GROUP. ALL MATERIAL
APPEARING HEREIN IS IN THE PUBLIC DOMAIN.
5. SERVICE AND SUPPORT TO THE TROOPS FROM ONE OF THE
US ARMY"S FINEST COMMUNICATIONS OPERATIONS CHIEFS OF
THE 1ST INFANTRY DIVISION (FORWARD), FORMERLY LOCATED
A COOKE BARRACKS, GOEPPINGEN, NEAR STUTTGART, GERMANY.
BT
0033
NNNN
Here's one of the most interesting ones. All net discipline is exactly as received. The "?" character was used in the message to replace ones that aren't in ITA2. Any format changes, such as stripping leading blanks, were done by Blogger, not me:
VV HNA033
RR RUWMKSM
DE RUMLNHA 0033 1410200
ZNR UUUUU
R 200131Z MAY 08
FM COMMCENTER AT YAHOOGROUPS.COM //NNN7DXB//
TO KSM MARINE RADIO SAN FRANCISCO CA //KSM BCST//
BT
UNCLAS
SUBJ: ACP-127 FORMATTED MESSAGE
REF: ACP-127 TAPE RELAY INSTRUCTIONS ( )
1. THIS IS AN EXAMPLE OF A MILITARY MESSAGE FORMATTED IN
THE ACP-127 TELETYPE TAPE RELAY FORMAT THAT WAS IN USE
IN THE US MILITARY PRIOR TO THE MID-1970S. DURING THE 1970S,
THE MILITARY TELETYPE TAPE RELAY SYSTEM, ALSO KNOWN AS
THE ?TORN TAPE RELAY SYSTEM? WAS SLOWLY REPLACED BY THE NEWER
AND FASTER AUTOMATIC DIGITIAL NETWORK, OR ?AUTODIN?.
2. AUTODIN WAS A HIGH-SPEED, HIGH CAPACITY, COMPUTER CONTROLLED
?SUPER TELETYPE? SYSTEM THAT WAS ALSO CAPABLE OF HANDLING
DATA TRAFFIC IN IBM PUNCHED CARD FORM (HOLLERITH CODE), AND
MAGNETIC MEDIA. IT RELIED ON SERVOS AND TAPE DRIVES, AND LATER,
WAS UPGRADED WITH WHAT WE NOW REFER TO AS HARD DRIVES
THAT WERE ABOUT THE SIZE OF WASHING MACHINES. SOME OF
THE MAIN BRAINS IN THE AUTODIN SYSTEM WERE RCA SPECTRE 70
PAGE 2 RUMLNHA0033 UNCLAS
MAIN FRAME COMPUTERS. MOST ARMY AUTODIN FACILITIES WERE
MAINTAINED BY EITHER PHILCO-FORD OR WESTERN UNION UNDER
DOD CONTRACT. AUTODIN ITSELF WAS FINALLY REPLACED ON
SEPTEMBER 30, 2003 BY A NEW MEDIUM CALLED THE DEFENSE
MESSAGING SYSTEM, OR ?DMS?. DMS OFFERS MORE CAPACITY THAN
DID AUTODIN. IT PERMITS ATTACHMENTS, GRAPHICS, MAPS, MAP
OVERLAYS, LETTERS AND NON-MESSAGE CORRESPONDENCE, FILES,
AND EMAIL TRAFFIC TO BE TRANSMITTED IN A SINGLE SECURE SYSTEM
THAT IS WORLDWIDE IN SCOPE AND OPERATION.
3. ACP-127 PROCEDURES HOWEVER, DIDN"T GO AWAY. MOST US
MILITARY TACTICAL CIRCUITS STILL USED ACP-127 FORMATS UNTIL
THE LATE 1980S, UNTIL THE AUTODIN SYSTEM WAS FINALLY
INTEGRATED IN THE FIELD UNITS. NATO UNITS CONTINUED TO USE
ACP-127 FORMATS, SINCE NONE OF THEIR EQUIPMENTS OR SYSTEMS
WERE COMPATIBLE WITH THE US COMPUTERIZED FORMAT. SYSTEM
COMPATIBILITY IN THOSE DAYS WAS CALLED ?INTEROPERABILITY?.
EVEN TODAY, ACP-127 FORMATS CAN STILL BE FOUND IN SOME
NATO COUNTRIES WHERE INTEROPERABILITY ISSUES CONTINUE
TO PERSIST.
4. TRANSMITTED AS AN INFORMATIONAL SERVICE BY THE
PAGE 3 RUMLNHA0033 UNCLAS
COMMCENTER AT YAHOOGROUPS.COM GROUP. ALL MATERIAL
APPEARING HEREIN IS IN THE PUBLIC DOMAIN.
5. SERVICE AND SUPPORT TO THE TROOPS FROM ONE OF THE
US ARMY"S FINEST COMMUNICATIONS OPERATIONS CHIEFS OF
THE 1ST INFANTRY DIVISION (FORWARD), FORMERLY LOCATED
A COOKE BARRACKS, GOEPPINGEN, NEAR STUTTGART, GERMANY.
BT
0033
NNNN
Monday, May 19, 2008
Digital Mode of the Week: PACTOR
PACTOR® (from Latin "the mediator," also a possible play on PACket plus amTOR) was developed by German hams in the early 1990s. It was originally intended to deal with the limitations of packet radio and AMTOR over noisy and fading HF circuits. It has become something of a de facto standard for HF e-mail systems, not only in amateur bands but also in commercial networks used by ships at sea and by nongovernmental organizations working in isolated areas.
PACTOR was originally based on the clever idea of using the good features of HF packet (robust error checking) and of AMTOR/SITOR (tight sync, short packet lengths), while eliminating the bad ones. The data bursts are longer than SITOR's, greatly reducing the timing demands on equipment. The protocol is better suited to HF than AX.25 packet, meaning fewer retries. Much of the time, PACTOR outperforms both modes in real-world band conditions.
The original mode is called PACTOR-I (Roman numeral one). The company has been speeding it up and adding features ever since, to the point where PACTOR-I is now rather slow and primitive by comparison.
PACTOR-I is a half-duplex, synchronous, ARQ mode which uses connections. The initiating station operates in "master" mode, while the called station is the "slave." Stations then take turns as information sending and receiving stations. The receiving station does a Cyclic Redundancy Check (CRC) on the packets, and transmits a brief ACK/NAK Control Signal (CS). In order to speed things up, a system called "memory ARQ" is used to compare packets and reduce repetition. In the original SCS equipment, this feature used an extremely clever analog algorithm.
There is also a PACTOR-I FEC mode. This does not use connections, but something resembling the "unproto" mode in packet. Frames are repeated and padded out with character 21 if nothing is in the send buffer.
PACTOR-I packet lengths are 96 bits in the slow mode (100 baud) and 192 at 200 baud. The modems are able to choose the appropriate data rate based on error responses from the receiver. PACTOR uses online data compression to further speed up throughput. Text is ASCII using Huffman coding (which prints as garbage unless decoded), falling back to straight ASCII when necessary or for calling.
PACTOR-I modulation is frequency-shift keying (FSK/AFSK), 200-Hertz shift. Like packet, the bits are in the state transitions, so it can be successfully tuned in either USB or LSB without changing polarity. For this reason, amateur mailboxes often list PACTOR frequencies by their center of intelligence, between the two original FSK tones, which then are +/- 100 Hz. LSB dial/window reading will then be the center frequency plus the audio center of your modem or software. On USB, you subtract the audio center.
PACTOR-I has been released for use in any 3rd party products, including modems and multimode sound card programs. It can be considered a standard. Everything else, however, remains completely proprietary to SCS, the German company started by PACTOR's inventors, or its licensees. The company has also worked with large commercial networks such as Globe Wireless to adapt PACTOR into even more proprietary modes.
SCS modems are high-end products for professional use, and they are priced accordingly. There has been some criticism from hams that these prices are a bit out of reach for amateurs. SCS has answered with a simplified PACTOR modem, the PTC-IIex, that lists for "only" 614 Euros as opposed to 1025 Euros for the full-featured version. Of course, either of these prices is a steal compared to the staggeringly expensive WAVECOM and HOKA multimode packages that will do all PACTOR's modes.
Out in the real world, PACTOR-I is used mostly for calling. Some people are still reporting traffic in it, but otherwise you'll be able to tell it's PACTOR and grab a callsign or two, then things will get weird in a hurry as the modems adapt. They'll start to switch quickly through a truly bewildering number of highly advanced modes that remain available only in boxes made or licensed by SCS.
PACTOR-II adds several more compression and coding features, and switches the modem to differential phase-shift keying (DPSK) to save spectrum. The sound changes from the well known lazy brrrrrrp brrrrrrp brrrrrrp to various hisses and buzzes usually otherwise heard in advanced military modes. Throughput increases from 100/200 baud to a best case 1200 bits/sec using compression.
The current hot setup is PACTOR-III, which adds yet more features to the firmware in existing SCS modems. Users can try these features for 20 connects, then a license is required. This one goes at a screaming best case throughput of 5200 bits/sec, though in doing so it becomes very wide indeed (2.4 kHz), with 18 tones and a physical bitrate of 3600/sec.
Here's a list of PACTOR modulations:
PACTOR-I:
FSK, 200 Hz, 100/200 baud
PACTOR-II (uncompressed)
2 tone DBPSK, 200 b/s physical, 100 b/s throughput
2 tone DQPSK, 400 b/s, 200
2 tone 8-DPSK, 600 b/s, 400
2 tone 16-DPSK, 800 b/s, 700
PACTOR-III (uncompressed)
2 tones, 200 b/s physical, 76.8 net data rate
6 tones, 600 b/s, 247.5
14 tones, 1400 b/s, 588.8
16 tones, 3200 b/s, 2039.5
18 tones, 3600 b/s, 2722.1
Pactor-III also has many submodes depending on various combinations of tones and DBPSK vs DQPSK.
In all modems, the maximum speed level can be set by the user.
--
Legal note: PACTOR® is a registered trademark of SCS, Germany.
http://www.scs-ptc.com/
PACTOR was originally based on the clever idea of using the good features of HF packet (robust error checking) and of AMTOR/SITOR (tight sync, short packet lengths), while eliminating the bad ones. The data bursts are longer than SITOR's, greatly reducing the timing demands on equipment. The protocol is better suited to HF than AX.25 packet, meaning fewer retries. Much of the time, PACTOR outperforms both modes in real-world band conditions.
The original mode is called PACTOR-I (Roman numeral one). The company has been speeding it up and adding features ever since, to the point where PACTOR-I is now rather slow and primitive by comparison.
PACTOR-I is a half-duplex, synchronous, ARQ mode which uses connections. The initiating station operates in "master" mode, while the called station is the "slave." Stations then take turns as information sending and receiving stations. The receiving station does a Cyclic Redundancy Check (CRC) on the packets, and transmits a brief ACK/NAK Control Signal (CS). In order to speed things up, a system called "memory ARQ" is used to compare packets and reduce repetition. In the original SCS equipment, this feature used an extremely clever analog algorithm.
There is also a PACTOR-I FEC mode. This does not use connections, but something resembling the "unproto" mode in packet. Frames are repeated and padded out with character 21 if nothing is in the send buffer.
PACTOR-I packet lengths are 96 bits in the slow mode (100 baud) and 192 at 200 baud. The modems are able to choose the appropriate data rate based on error responses from the receiver. PACTOR uses online data compression to further speed up throughput. Text is ASCII using Huffman coding (which prints as garbage unless decoded), falling back to straight ASCII when necessary or for calling.
PACTOR-I modulation is frequency-shift keying (FSK/AFSK), 200-Hertz shift. Like packet, the bits are in the state transitions, so it can be successfully tuned in either USB or LSB without changing polarity. For this reason, amateur mailboxes often list PACTOR frequencies by their center of intelligence, between the two original FSK tones, which then are +/- 100 Hz. LSB dial/window reading will then be the center frequency plus the audio center of your modem or software. On USB, you subtract the audio center.
PACTOR-I has been released for use in any 3rd party products, including modems and multimode sound card programs. It can be considered a standard. Everything else, however, remains completely proprietary to SCS, the German company started by PACTOR's inventors, or its licensees. The company has also worked with large commercial networks such as Globe Wireless to adapt PACTOR into even more proprietary modes.
SCS modems are high-end products for professional use, and they are priced accordingly. There has been some criticism from hams that these prices are a bit out of reach for amateurs. SCS has answered with a simplified PACTOR modem, the PTC-IIex, that lists for "only" 614 Euros as opposed to 1025 Euros for the full-featured version. Of course, either of these prices is a steal compared to the staggeringly expensive WAVECOM and HOKA multimode packages that will do all PACTOR's modes.
Out in the real world, PACTOR-I is used mostly for calling. Some people are still reporting traffic in it, but otherwise you'll be able to tell it's PACTOR and grab a callsign or two, then things will get weird in a hurry as the modems adapt. They'll start to switch quickly through a truly bewildering number of highly advanced modes that remain available only in boxes made or licensed by SCS.
PACTOR-II adds several more compression and coding features, and switches the modem to differential phase-shift keying (DPSK) to save spectrum. The sound changes from the well known lazy brrrrrrp brrrrrrp brrrrrrp to various hisses and buzzes usually otherwise heard in advanced military modes. Throughput increases from 100/200 baud to a best case 1200 bits/sec using compression.
The current hot setup is PACTOR-III, which adds yet more features to the firmware in existing SCS modems. Users can try these features for 20 connects, then a license is required. This one goes at a screaming best case throughput of 5200 bits/sec, though in doing so it becomes very wide indeed (2.4 kHz), with 18 tones and a physical bitrate of 3600/sec.
Here's a list of PACTOR modulations:
PACTOR-I:
FSK, 200 Hz, 100/200 baud
PACTOR-II (uncompressed)
2 tone DBPSK, 200 b/s physical, 100 b/s throughput
2 tone DQPSK, 400 b/s, 200
2 tone 8-DPSK, 600 b/s, 400
2 tone 16-DPSK, 800 b/s, 700
PACTOR-III (uncompressed)
2 tones, 200 b/s physical, 76.8 net data rate
6 tones, 600 b/s, 247.5
14 tones, 1400 b/s, 588.8
16 tones, 3200 b/s, 2039.5
18 tones, 3600 b/s, 2722.1
Pactor-III also has many submodes depending on various combinations of tones and DBPSK vs DQPSK.
In all modems, the maximum speed level can be set by the user.
--
Legal note: PACTOR® is a registered trademark of SCS, Germany.
http://www.scs-ptc.com/
Thursday, May 08, 2008
FCC Denies Miller Digital Bandwidth Petition
In a Report and Order in the matter of RM-11392, the FCC has denied a rule making petition by amateur Mark Miller regarding bandwidth and frequencies used for digital modes, especially by automatically controlled stations.
Miller's argument was that the adoption of wideband data and image transmission by new generations of computer-oriented hams would clog the subbands now being used for such older modes as RTTY. He asked for tighter limits on these, more or less rolling back the FCC rules to before 2006. He noted his awareness that this would also effectively ban Pactor-III and ALE, but that was the price of good spectrum management.
Most of the 650 comments were negative, and Miller's filing had been widely derogated as the "digital stone age petition." The FCC agreed that he had not made a good case that rule changes were necessary.
Miller's argument was that the adoption of wideband data and image transmission by new generations of computer-oriented hams would clog the subbands now being used for such older modes as RTTY. He asked for tighter limits on these, more or less rolling back the FCC rules to before 2006. He noted his awareness that this would also effectively ban Pactor-III and ALE, but that was the price of good spectrum management.
Most of the 650 comments were negative, and Miller's filing had been widely derogated as the "digital stone age petition." The FCC agreed that he had not made a good case that rule changes were necessary.
Armed Forces Day SECDEF Message This Saturday
From Army MARS:
SECRETARY OF DEFENSE MESSAGE TEST VIA DIGITAL MODES.
The Secretary of Defense message will be transmitted via digital modes including RTTY, PACTOR, AMTOR, PSK-31, MFSK and MT63 from the stations listed below, including frequencies, mode, and date/time in Zulu (UTC). All frequencies are listed for center of intelligence. Offset as appropriate for your TNC. (Note: Not all stations may necessarily operate on all the frequencies listed, depending on propagation and available equipment.)
Army Stations
STATION: AAZ (HQ Army MARS Gateway, Fort Huachuca, Arizona)
6988.0 kHz
RTTY 11 May 0110Z
PACTOR FEC 11 May 0130Z
MT63 11 May 0220Z
PSK-31 11 May 0250Z
14402.0 kHz
RTTY 11 May 0110Z
PACTOR FEC 11 May 0130Z
MT63 11 May 0220Z
PSK-31 11 May 0250Z
STATION: WAR (Pentagon ARC/MARS Station, Arlington, Virginia)
6988.0 kHz
RTTY 10 May 1700Z
RTTY 10 May 2300Z
MT63 10 May 1715Z
MT63 10 May 2315Z
14440.0 kHz
PACTOR FEC 10 May 1730Z
PACTOR FEC 10 May 2330Z
Olivia 10 May 1745Z
Olivia 10 May 2345Z
Stations copying the Secretary of Defense message transmitted from AAZ/WAR should send their entries to Armed Forces Day Celebration, Commander NETCOM/9th ASC, Attn: NETC-OPE-MA (MARS) (31), Fort Huachuca, AZ 85613-5000.
Air Force Stations
STATION: AIR-2 (Scott Air Force Base)
7831.1 kHz
RTTY 10 May/1930Z
PACTOR 10 May/2000Z
MT63 10 May/2030Z
MFSK 10 May/2100Z
14877.1 kHz
RTTY 10 May/2130Z
PACTOR 10 May/2200Z
MT63 10 May/2230Z
MFSK 10 May/2300Z
Navy/Marine Corps Stations
STATION: NAV (HQ NAVMARCORMARS Radio Station, WILLIAMSBURG, VA)
7346.5 kHz
RTTY 75 baud 10 May/2340Z
AMTOR FEC 11 May/0010Z
MT63 11 May/0040Z
14480.0 kHz
RTTY 75 baud 10 May/2340Z
AMTOR FEC 11 May/0010Z
MT63 11 May/0040Z
STATION: NAV3 (NAVMARCORMARS Radio Station, CORPUS CHRISTI, TX)
7393.0 kHz
RTTY 10 May/2340Z
AMTOR FEC 11 May/0010Z
MT63 11 May/0040Z
13975.5 kHz
RTTY 10 May/2340Z
AMTOR FEC 11 May/0010Z
MT63 11 May/0040Z
STATION: NAV4 (NAVMARCORMARS Radio Station, GREAT LAKES, IL)
7375.0 kHz
RTTY 11 May/0240Z
AMTOR FEC 11 May/0310Z
MT63 11 May/0340Z
14468.5 kHz
RTTY 11 May/0240Z
AMTOR FEC 11 May/0310Z
MT63 11 May/0340Z
STATION: NBL (NAVMARCORMARS Radio Station, GROTON, CT)
7370.0 kHz
RTTY 10 May/2340Z
PACTOR FEC 11 May/0010Z
AMTOR FEC 11 May/0040Z
14393.0 kHz
RTTY 10 May/2340Z
PACTOR FEC 11 May/0010Z
AMTOR FEC 11 May/0040Z
STATION: NPL (NAVMARCORMARS Radio Station, SAN DIEGO, CA)
7350.0 kHz
RTTY 11 May/0240Z
PACTOR FEC 11 May/0310Z
AMTOR FEC 11 May/0340Z
14465.0 kHz
RTTY 11 May/0410Z
PACTOR FEC 11 May/0440Z
AMTOR FEC 11 May/0510Z
STATION: NUW (NAVMARCORMARS Radio Station, NAS WHIDBEY
ISLAND, WA)
7380.0 kHz
RTTY 11 May/0240Z
PACTOR FEC 11 May/0310Z
AMTOR FEC 11 May/0340Z
13530.0 kHz RTTY 11 May/0410Z
PACTOR FEC 11 May/0440Z
AMTOR FEC 11 May/0510Z
SUBMISSION OF SECRETARY OF DEFENSE TEST MESSAGE ENTRIES.
Transcripts of the RTTY, PACTOR, AMTOR, PSK-31, MFSK and MT63 receiving test should be submitted "as received". No attempt should be made to correct possible transmission errors. Provide time, frequency and call sign of the military station copied, including name, call sign, and address (including ZIP code) of individual submitting the entry. Ensure this information is placed on the paper containing the test message. Each year a large number of acceptable entries are received with insufficient information, or necessary information was not attached to the transcriptions and was separated, thereby precluding issuance of a certificate. Entries must be sent to the appropriate military address as follows:
a. Stations copying Secretary of Defense message transmitted from AAZ send entries to:
Armed Forces Day Celebration
Commander NETCOM/9th ASC
Armed Forces Day Celebration
Attn: NETC-OPE-MA (MARS) (31)
Fort Huachuca, AZ 85613-5000
b. Stations copying Secretary of Defense message transmitted from NAV, NAV-3, NAV-
4, NBL, NPL or NUW send entries to:
Armed Forces Day Celebration
Chief, Navy-Marine Corps MARS
Cheatham Annex Bldg 117
108 Sanda Ave
Williamsburg, VA 23185-5830
c. Stations copying Secretary of Defense message transmitted from AIR-2 send entries
to:
Armed Forces Day Celebration
AFCA / Chief, AF MARS
203W Losey St
Scott AFB, IL 62225
Details of the amateur crossband transmitting test are here.
SECRETARY OF DEFENSE MESSAGE TEST VIA DIGITAL MODES.
The Secretary of Defense message will be transmitted via digital modes including RTTY, PACTOR, AMTOR, PSK-31, MFSK and MT63 from the stations listed below, including frequencies, mode, and date/time in Zulu (UTC). All frequencies are listed for center of intelligence. Offset as appropriate for your TNC. (Note: Not all stations may necessarily operate on all the frequencies listed, depending on propagation and available equipment.)
Army Stations
STATION: AAZ (HQ Army MARS Gateway, Fort Huachuca, Arizona)
6988.0 kHz
RTTY 11 May 0110Z
PACTOR FEC 11 May 0130Z
MT63 11 May 0220Z
PSK-31 11 May 0250Z
14402.0 kHz
RTTY 11 May 0110Z
PACTOR FEC 11 May 0130Z
MT63 11 May 0220Z
PSK-31 11 May 0250Z
STATION: WAR (Pentagon ARC/MARS Station, Arlington, Virginia)
6988.0 kHz
RTTY 10 May 1700Z
RTTY 10 May 2300Z
MT63 10 May 1715Z
MT63 10 May 2315Z
14440.0 kHz
PACTOR FEC 10 May 1730Z
PACTOR FEC 10 May 2330Z
Olivia 10 May 1745Z
Olivia 10 May 2345Z
Stations copying the Secretary of Defense message transmitted from AAZ/WAR should send their entries to Armed Forces Day Celebration, Commander NETCOM/9th ASC, Attn: NETC-OPE-MA (MARS) (31), Fort Huachuca, AZ 85613-5000.
Air Force Stations
STATION: AIR-2 (Scott Air Force Base)
7831.1 kHz
RTTY 10 May/1930Z
PACTOR 10 May/2000Z
MT63 10 May/2030Z
MFSK 10 May/2100Z
14877.1 kHz
RTTY 10 May/2130Z
PACTOR 10 May/2200Z
MT63 10 May/2230Z
MFSK 10 May/2300Z
Navy/Marine Corps Stations
STATION: NAV (HQ NAVMARCORMARS Radio Station, WILLIAMSBURG, VA)
7346.5 kHz
RTTY 75 baud 10 May/2340Z
AMTOR FEC 11 May/0010Z
MT63 11 May/0040Z
14480.0 kHz
RTTY 75 baud 10 May/2340Z
AMTOR FEC 11 May/0010Z
MT63 11 May/0040Z
STATION: NAV3 (NAVMARCORMARS Radio Station, CORPUS CHRISTI, TX)
7393.0 kHz
RTTY 10 May/2340Z
AMTOR FEC 11 May/0010Z
MT63 11 May/0040Z
13975.5 kHz
RTTY 10 May/2340Z
AMTOR FEC 11 May/0010Z
MT63 11 May/0040Z
STATION: NAV4 (NAVMARCORMARS Radio Station, GREAT LAKES, IL)
7375.0 kHz
RTTY 11 May/0240Z
AMTOR FEC 11 May/0310Z
MT63 11 May/0340Z
14468.5 kHz
RTTY 11 May/0240Z
AMTOR FEC 11 May/0310Z
MT63 11 May/0340Z
STATION: NBL (NAVMARCORMARS Radio Station, GROTON, CT)
7370.0 kHz
RTTY 10 May/2340Z
PACTOR FEC 11 May/0010Z
AMTOR FEC 11 May/0040Z
14393.0 kHz
RTTY 10 May/2340Z
PACTOR FEC 11 May/0010Z
AMTOR FEC 11 May/0040Z
STATION: NPL (NAVMARCORMARS Radio Station, SAN DIEGO, CA)
7350.0 kHz
RTTY 11 May/0240Z
PACTOR FEC 11 May/0310Z
AMTOR FEC 11 May/0340Z
14465.0 kHz
RTTY 11 May/0410Z
PACTOR FEC 11 May/0440Z
AMTOR FEC 11 May/0510Z
STATION: NUW (NAVMARCORMARS Radio Station, NAS WHIDBEY
ISLAND, WA)
7380.0 kHz
RTTY 11 May/0240Z
PACTOR FEC 11 May/0310Z
AMTOR FEC 11 May/0340Z
13530.0 kHz RTTY 11 May/0410Z
PACTOR FEC 11 May/0440Z
AMTOR FEC 11 May/0510Z
SUBMISSION OF SECRETARY OF DEFENSE TEST MESSAGE ENTRIES.
Transcripts of the RTTY, PACTOR, AMTOR, PSK-31, MFSK and MT63 receiving test should be submitted "as received". No attempt should be made to correct possible transmission errors. Provide time, frequency and call sign of the military station copied, including name, call sign, and address (including ZIP code) of individual submitting the entry. Ensure this information is placed on the paper containing the test message. Each year a large number of acceptable entries are received with insufficient information, or necessary information was not attached to the transcriptions and was separated, thereby precluding issuance of a certificate. Entries must be sent to the appropriate military address as follows:
a. Stations copying Secretary of Defense message transmitted from AAZ send entries to:
Armed Forces Day Celebration
Commander NETCOM/9th ASC
Armed Forces Day Celebration
Attn: NETC-OPE-MA (MARS) (31)
Fort Huachuca, AZ 85613-5000
b. Stations copying Secretary of Defense message transmitted from NAV, NAV-3, NAV-
4, NBL, NPL or NUW send entries to:
Armed Forces Day Celebration
Chief, Navy-Marine Corps MARS
Cheatham Annex Bldg 117
108 Sanda Ave
Williamsburg, VA 23185-5830
c. Stations copying Secretary of Defense message transmitted from AIR-2 send entries
to:
Armed Forces Day Celebration
AFCA / Chief, AF MARS
203W Losey St
Scott AFB, IL 62225
Details of the amateur crossband transmitting test are here.
US Army Corps of Engineers QSL Opportunity
From Jim Pogue:
[Editor's note: the annual Armed Forces Day crossband tests are done a week before AFD, so as not to conflict with the Dayton Hamvention.]
Once again, station WUG-231 will offer a special QSL card for SWLs only who hear our station during the ANNUAL ARMED FORCES DAY CROSSBAND MILITARY/AMATEUR RADIO COMMUNICATIONS TEST this Saturday, 10/11 MAY 2008.
Any SWL worldwide who hears us is invited to send a reception report and receive our special commemorative QSL card. This will be different than the one amateurs receive for any contacts they make with us.
You may send your report directly to me at the address below. No return postage is necessary. Frequencies are also listed below. Good luck and I hope to hear from you.
STATION: WUG-231 (10 May 1300Z - 11 May 0200Z)
Frequency Emission Amateur Band
4032.9 kHz LSB 80M
7.360.0 kHz LSB 40M
6.826.0 kHz LSB 40M
14486.0 kHz USB 20M
14663.5 kHz USB 20M
20973.5 kHz USB 15M
Location: Memphis, TN
Address:
USACE Memphis District Office
ATTN: Jim Pogue
Public Affairs Office Room B-202
167 N. Main St.
Memphis, TN 38103-1894
POC: Mr. Jim Pogue
Commercial: (901) 544-4109
[Editor's note: the annual Armed Forces Day crossband tests are done a week before AFD, so as not to conflict with the Dayton Hamvention.]
Wednesday, May 07, 2008
Digital Mode of the "Week:" HF Packet
This is early because I'm going on vacation.
---
"Packet Radio" is an amateur mode used to send data between terminals attached to radios. It really took off in the 80s after the authorization of ASCII on amateur bands. It gets its name from "packet switching," a networking protocol in which data is divided into small blocks (packets) with the address and sequence numbers attached. This allows a station to act as a "node," and connect to multiple users on the same frequency. Incidentally, you're using packet-switching and routing right now, since these are also used in the TCP/IP protocol suite which makes the Internet go.
HF packet, which is what we're interested in, is an adaptation of the VHF packet you might be more used to. It transmits at 300 baud, with a 200-Hz shift, using audio frequency-shift keying (AFSK) of standard single-sideband ham transceivers. Various tone centers have been used by different hardware Terminal Node Controllers (TNCs), with the most common being 2210 and 1700.
The AX.25 link-layer protocol used by amateur packet radio uses a special polarity (or lack therof) called NRZI (Non-Return to Zero Inverted). In this, any bit state transition is a one, and no transition is a zero. Since it's the transitions that matter, mark and space are in practice not relevant. This means that packet can be tuned in USB or LSB with no need to change polarity at the receiver. However, as in RTTY, the receiver dial frequencies are usually (though not always) closer to the listed ones in LSB mode.
Today, software TNCs have pretty much replaced hardware ones, but the underlying link-layer scheme is the same. It's just better hidden. AX.25 uses connections, meaning that one station will connect with the other before exchanging information. However an "unproto" mode is provided for CQs, and a "beacon" mode for all-station-this-net broadcasts. There's also a "monitor" mode, which is what we will use, because it decodes all the packets.
Packets are labeled for type of data, which for our purposes means that they are either control packets or data packets. A lot of control packets are sent, giving the mode a rather high overhead.
The receiving connected station will error-check packets and ask for retries of missed ones. Therefore packet radio, like SITOR-A, slows down as channel noise increases. Even at 300 baud, the need for retries can make real information throughput absolutely glacial, and HF packet just isn't used much for long messages. In extensive monitoring, I've seen a few BBS (Bulletin Board System) connections, a few compressed file transfers (which print as gibberish), and a lot of automatic forwarding of packets (aka "digipeating").
Plain text is 7-bit ASCII. TNCs can switch to 8-bit mode for binary transfers or extended characters, but the one at the other end has to do same.
HF packet sounds like a series of short buzzes. These are much shorter and chirpier sounding than other modes used for e-mail and such. Given the greater chance that long packets will be rejected, it's best to keep the bursts very short.
One interesting mode that is run as an application on top of packet is Automatic Position Reporting System (APRS). This automatically sends the GPS position of the station, or even such data as the weather. It allows hams to track vehicles out in the boonies, or participate in weather observing networks. These are then forwarded to multiple stations, and plotted using slick map software. Obviously, HF has considerable potential here due to its coverage of areas where VHF is unheard of.
The best HF frequency for APRS is listed as 10147.6 USB. This is the worldwide APRS gateway. My receiver gives a 1700-Hz tone center when tuned in this mode. I have it on right now, and an HF station just reported a position in California. This is cool stuff.
---
"Packet Radio" is an amateur mode used to send data between terminals attached to radios. It really took off in the 80s after the authorization of ASCII on amateur bands. It gets its name from "packet switching," a networking protocol in which data is divided into small blocks (packets) with the address and sequence numbers attached. This allows a station to act as a "node," and connect to multiple users on the same frequency. Incidentally, you're using packet-switching and routing right now, since these are also used in the TCP/IP protocol suite which makes the Internet go.
HF packet, which is what we're interested in, is an adaptation of the VHF packet you might be more used to. It transmits at 300 baud, with a 200-Hz shift, using audio frequency-shift keying (AFSK) of standard single-sideband ham transceivers. Various tone centers have been used by different hardware Terminal Node Controllers (TNCs), with the most common being 2210 and 1700.
The AX.25 link-layer protocol used by amateur packet radio uses a special polarity (or lack therof) called NRZI (Non-Return to Zero Inverted). In this, any bit state transition is a one, and no transition is a zero. Since it's the transitions that matter, mark and space are in practice not relevant. This means that packet can be tuned in USB or LSB with no need to change polarity at the receiver. However, as in RTTY, the receiver dial frequencies are usually (though not always) closer to the listed ones in LSB mode.
Today, software TNCs have pretty much replaced hardware ones, but the underlying link-layer scheme is the same. It's just better hidden. AX.25 uses connections, meaning that one station will connect with the other before exchanging information. However an "unproto" mode is provided for CQs, and a "beacon" mode for all-station-this-net broadcasts. There's also a "monitor" mode, which is what we will use, because it decodes all the packets.
Packets are labeled for type of data, which for our purposes means that they are either control packets or data packets. A lot of control packets are sent, giving the mode a rather high overhead.
The receiving connected station will error-check packets and ask for retries of missed ones. Therefore packet radio, like SITOR-A, slows down as channel noise increases. Even at 300 baud, the need for retries can make real information throughput absolutely glacial, and HF packet just isn't used much for long messages. In extensive monitoring, I've seen a few BBS (Bulletin Board System) connections, a few compressed file transfers (which print as gibberish), and a lot of automatic forwarding of packets (aka "digipeating").
Plain text is 7-bit ASCII. TNCs can switch to 8-bit mode for binary transfers or extended characters, but the one at the other end has to do same.
HF packet sounds like a series of short buzzes. These are much shorter and chirpier sounding than other modes used for e-mail and such. Given the greater chance that long packets will be rejected, it's best to keep the bursts very short.
One interesting mode that is run as an application on top of packet is Automatic Position Reporting System (APRS). This automatically sends the GPS position of the station, or even such data as the weather. It allows hams to track vehicles out in the boonies, or participate in weather observing networks. These are then forwarded to multiple stations, and plotted using slick map software. Obviously, HF has considerable potential here due to its coverage of areas where VHF is unheard of.
The best HF frequency for APRS is listed as 10147.6 USB. This is the worldwide APRS gateway. My receiver gives a 1700-Hz tone center when tuned in this mode. I have it on right now, and an HF station just reported a position in California. This is cool stuff.
Sunday, May 04, 2008
Digital Mode of the Week: ASCII
ASCII stands for American Standard Code for Information Interchange. It was developed in the United States as a standard means of encoding text readable by people as bits readable by digital computers. It gradually replaced other such American codes as IBM's EBCDIC and Commodore's PETSCII. US ASCII is something of a de facto standard worldwide.
You're using ASCII right now. It's still the basis for most of the text characters used by computers, although as a subset of several much larger character sets that are now used. Plain text files are still usually straight ASCII. It's still fundamental to most of our digital modes.
ASCII was originally developed at Bell Labs for use with wireline TWX machines (an AT&T version of the Teletype). It is essentially an expansion and reordering of ITA2 to make it more useful to computers or "dumb" terminals with modems attached. Today's ASCII is a 7-bit asynchronous code with 128 characters (starting at zero). The first 33 characters (0-32) are non-printing, consisting of null (all zeroes) plus a number of control codes, and the space/blank character (decimal 32).
ASCII can, of course, be sent by frequency-shift keying, and in fact it wasn't long before hams investigated its use as an improvement to radioteletype (RTTY). However, its greater complexity and speed made results on noisy HF circuits disappointing at best when just using straight ASCII. Instead, it's usually sent by packet radio or other error-checking teleprinting schemes.
ASCII characters are sent with "framing" consisting of one start bit and one or two stop bits (remember Baudot's use of a longer stop). Characters usually map to bytes, and since these have 8 bits in modern computers, there's a bit left over. Various things are done with this extra bit.
Many modems have the option to use this 8th bit as a parity bit. This gives a rudimentary error check. If parity is used, the 8th bit will be set or unset so that every character has an even number of ones (even parity) or an odd number (odd parity). If parity is turned off on 7-bit ASCII, the receiver will (hopefully) ignore the 8th bit.
The 8th bit is also used to expand the character set to the full 255. Although SHIFT IN and SHIFT OUT are provided, setting this bit can also send the expanded characters, essentially treating ASCII as an 8-bit code with no parity check.
Unfortunately, there's no international standard for this, and technically it's something of a misnomer to apply the name ASCII to all 8 bits. The high-bit characters are often dependent on application. They can contain accented letters and symbols used in a particular language, or little pieces of lines and corners useful for drawing boxes on old text based terminals.
All of this leads to those infamous ASCII receiver setup parameters that are used in most of our digital modes. These are character length (7 or 8 data bits), stop bits (one or two), and parity (odd, even, or none). While some straight ASCII software can autobaud, it's usually also necessary to set the baud rate by hand. Common HF rates are 100, 110, 300, 600, 1200, 1800, and 2400.
Usually getting all this right in a short wave listening situation is by trial and error. It helps that there are really only two settings in common use. These are 7E1 (7 data bits, even parity, one stop bit), and 8N1 (eight data bits, no parity, one stop bit). It is also possible to emulate the old ITA2 alphabet by simply transmitting the appropriate character set in 5N1 or 5N2 (5 data bits, no parity, one or two stop bits). You see this done by the French Navy when sending data in newer modes such as STANAG 4285.
Here's the 7-bit ASCII in a compact table found on Wikipedia:
An expanded listing of this code is at this column's web site.
You're using ASCII right now. It's still the basis for most of the text characters used by computers, although as a subset of several much larger character sets that are now used. Plain text files are still usually straight ASCII. It's still fundamental to most of our digital modes.
ASCII was originally developed at Bell Labs for use with wireline TWX machines (an AT&T version of the Teletype). It is essentially an expansion and reordering of ITA2 to make it more useful to computers or "dumb" terminals with modems attached. Today's ASCII is a 7-bit asynchronous code with 128 characters (starting at zero). The first 33 characters (0-32) are non-printing, consisting of null (all zeroes) plus a number of control codes, and the space/blank character (decimal 32).
ASCII can, of course, be sent by frequency-shift keying, and in fact it wasn't long before hams investigated its use as an improvement to radioteletype (RTTY). However, its greater complexity and speed made results on noisy HF circuits disappointing at best when just using straight ASCII. Instead, it's usually sent by packet radio or other error-checking teleprinting schemes.
ASCII characters are sent with "framing" consisting of one start bit and one or two stop bits (remember Baudot's use of a longer stop). Characters usually map to bytes, and since these have 8 bits in modern computers, there's a bit left over. Various things are done with this extra bit.
Many modems have the option to use this 8th bit as a parity bit. This gives a rudimentary error check. If parity is used, the 8th bit will be set or unset so that every character has an even number of ones (even parity) or an odd number (odd parity). If parity is turned off on 7-bit ASCII, the receiver will (hopefully) ignore the 8th bit.
The 8th bit is also used to expand the character set to the full 255. Although SHIFT IN and SHIFT OUT are provided, setting this bit can also send the expanded characters, essentially treating ASCII as an 8-bit code with no parity check.
Unfortunately, there's no international standard for this, and technically it's something of a misnomer to apply the name ASCII to all 8 bits. The high-bit characters are often dependent on application. They can contain accented letters and symbols used in a particular language, or little pieces of lines and corners useful for drawing boxes on old text based terminals.
All of this leads to those infamous ASCII receiver setup parameters that are used in most of our digital modes. These are character length (7 or 8 data bits), stop bits (one or two), and parity (odd, even, or none). While some straight ASCII software can autobaud, it's usually also necessary to set the baud rate by hand. Common HF rates are 100, 110, 300, 600, 1200, 1800, and 2400.
Usually getting all this right in a short wave listening situation is by trial and error. It helps that there are really only two settings in common use. These are 7E1 (7 data bits, even parity, one stop bit), and 8N1 (eight data bits, no parity, one stop bit). It is also possible to emulate the old ITA2 alphabet by simply transmitting the appropriate character set in 5N1 or 5N2 (5 data bits, no parity, one or two stop bits). You see this done by the French Navy when sending data in newer modes such as STANAG 4285.
Here's the 7-bit ASCII in a compact table found on Wikipedia:
An expanded listing of this code is at this column's web site.
Friday, May 02, 2008
KSM Encrypted Broadcast WILL Take Place May 3
KSM's intrepid transmitter engineer has recovered sufficiently to come to the station and make the encrypted RTTY and SITOR-B broadcasts using a classic US military crypto machine from World War II. Details are as follows:
Times: Approximately 1900 and 2100 UTC on May 3.
Assigned frequencies: 8433.0 and 12631.0.
Modes: RTTY and FEC. Baudot transmissions are at 170cps shift, 45 baud. FEC transmissions are at 170cps shift, 100 baud (SITOR-B).
Text will start with a plaintext preamble and will include the settings for the M-209 as well as the key. That will be followed by the encrypted text in five letter groups. Since hardly anyone has an M-209, a software emulator is available here. I have been playing with this, and it's a very slick program.
K6KPH will guard its usual CW frequencies of 7050, 14050, 21050 (3550 on request). Since these frequencies are in the scan with the ship calling frequencies the best bet is to use commercial calling procedure: repeat "K6KPH" (within the limits of FCC identification requirements of course) until the K6KPH operator responds with "DE", then send your call and traffic.
QSL, as always, is to Denice Stoops, PO Box 381, Bolinas, California 94926 USA.
Maritime Radio Historical Society web site
Times: Approximately 1900 and 2100 UTC on May 3.
Assigned frequencies: 8433.0 and 12631.0.
Modes: RTTY and FEC. Baudot transmissions are at 170cps shift, 45 baud. FEC transmissions are at 170cps shift, 100 baud (SITOR-B).
Text will start with a plaintext preamble and will include the settings for the M-209 as well as the key. That will be followed by the encrypted text in five letter groups. Since hardly anyone has an M-209, a software emulator is available here. I have been playing with this, and it's a very slick program.
K6KPH will guard its usual CW frequencies of 7050, 14050, 21050 (3550 on request). Since these frequencies are in the scan with the ship calling frequencies the best bet is to use commercial calling procedure: repeat "K6KPH" (within the limits of FCC identification requirements of course) until the K6KPH operator responds with "DE", then send your call and traffic.
QSL, as always, is to Denice Stoops, PO Box 381, Bolinas, California 94926 USA.
Maritime Radio Historical Society web site
IARU Simulated Emergency Test Is May 3
For us, the most interesting feature of this event is the use of Automatic Link Establishment on amateur frequencies. From International Amateur Radio Union:
HFN is the amateur Global High Frequency Network. The network frequencies and pilot stations are:
3596.0
7102.0
10145.5
14109.0
18106.0
21096.0
24926.0
28146.0
ALE Net: HFN
SLOT
1 [ User's callsign ]
2 KM4BA
3 KQ6XA
4 WA3MEZ
5 K7EK
6 VE2FXL
7 NJ7C
8 WD8ARZ
9 KN0CK
10 N0PWZ
Amateurs will attempt to link up with these stations and pass their emergency power capability in an AMD (Automatic Message of the Day).
While it is not clear, presumably May 3 begins at 0000 UTC, which is on the 2nd in the US. In fact, it is about an hour from this posting.
A "qrg" (frequency) file is available at hflink.com. If you join their Yahoo! group, you can also get the latest version of PC-ALE, which will scan (MultiPSK and SkySweeper won't). I've got it going here, and it seems much more sensitive than previous versions. Thanks to the hflink administrators for making it available to me.
It is important NOT to attempt to transmit ALE with amateur equipment unless you know what you are doing. It's not designed to change bands this fast unless you are using a good autotuner and antenna(s) for all bands. In addition, the amateur rules impose certain technical issues. Read the materials out on the Internet before trying this mode!!!!!!
Operators participate in the Global Simulated Emergency Test by sending ALE text messages to the central IARU GlobalSET European headquarters relayed via the network of ALE Global HFN Pilot Stations. Hams activate their ALE stations, start scanning and sounding before the event, and send messages during the day of the event. In addition to the emergency practice, this provides valuable
knowledge of the resources that can be mobilized in the event of a real emergency.
HFN is the amateur Global High Frequency Network. The network frequencies and pilot stations are:
3596.0
7102.0
10145.5
14109.0
18106.0
21096.0
24926.0
28146.0
ALE Net: HFN
SLOT
1 [ User's callsign ]
2 KM4BA
3 KQ6XA
4 WA3MEZ
5 K7EK
6 VE2FXL
7 NJ7C
8 WD8ARZ
9 KN0CK
10 N0PWZ
Amateurs will attempt to link up with these stations and pass their emergency power capability in an AMD (Automatic Message of the Day).
While it is not clear, presumably May 3 begins at 0000 UTC, which is on the 2nd in the US. In fact, it is about an hour from this posting.
A "qrg" (frequency) file is available at hflink.com. If you join their Yahoo! group, you can also get the latest version of PC-ALE, which will scan (MultiPSK and SkySweeper won't). I've got it going here, and it seems much more sensitive than previous versions. Thanks to the hflink administrators for making it available to me.
It is important NOT to attempt to transmit ALE with amateur equipment unless you know what you are doing. It's not designed to change bands this fast unless you are using a good autotuner and antenna(s) for all bands. In addition, the amateur rules impose certain technical issues. Read the materials out on the Internet before trying this mode!!!!!!
US/NATO Joint Exercise On Until May 14
From Combinedendeavor.net
What this means in standard English is that this annual communication/ interoperability exercise always brings out some good (often unencrypted) digital military exercise traffic in Europe.
Welcome to Combined Endeavor 2008!
This annual, United States European Command (USEUCOM)-sponsored exercise is “in the spirit of” the Partnership for Peace (PfP) C4 Integration and Interoperability Exercise. CE enables interoperability between U.S. and NATO / PfP military C4 equipment by documenting and exercising technical and procedural solutions.
What this means in standard English is that this annual communication/ interoperability exercise always brings out some good (often unencrypted) digital military exercise traffic in Europe.
Thursday, May 01, 2008
Charles Brain's Web Site Vanishes
Those looking for Charles Brain's web site with the "official" distributions of PC-ALE and PC-HFDL got a rude surprise today when it vanished. Those taking the link got a blank white page with the cryptic, "I am sorry but my website got deleted."
The last "official" stable release of PC-HFDL, version 2.031, is still available on this column's web site. It was put there originally by request of Charles to help with his bandwidth issues, and it is a copy of the official msi file in a zip folder.
Since the beta 2.04 was never "officially" released, I won't put it up unless asked to, even though I have the distribution zip archive, and the program has always worked just fine here.
The latest stable, non-MARS version of PC-ALE is 1.062G. There's a beta of 1.062H available here. This one is really intended for amateur radio use, though I have gotten it to work for utilities simply by changing the frequencies and group names in the QRG file. There has been some grumbling about this program by those who preferred the old, terse, rather inscrutable user interface. However, it's the one in use here.
While checking all this, I notice that the frequency 14109.0 is now the amateur ALE "pilot channel," though 14109.5 will be scanned until July of 2008.
The last "official" stable release of PC-HFDL, version 2.031, is still available on this column's web site. It was put there originally by request of Charles to help with his bandwidth issues, and it is a copy of the official msi file in a zip folder.
Since the beta 2.04 was never "officially" released, I won't put it up unless asked to, even though I have the distribution zip archive, and the program has always worked just fine here.
The latest stable, non-MARS version of PC-ALE is 1.062G. There's a beta of 1.062H available here. This one is really intended for amateur radio use, though I have gotten it to work for utilities simply by changing the frequencies and group names in the QRG file. There has been some grumbling about this program by those who preferred the old, terse, rather inscrutable user interface. However, it's the one in use here.
While checking all this, I notice that the frequency 14109.0 is now the amateur ALE "pilot channel," though 14109.5 will be scanned until July of 2008.
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