Yesterday, a discussion on the HFDL Yahoo group produced the intelligence that the frequencies were being changed in bunches. As a result, it was predicted that ARINC would soon change the system table again.
They did.
You know the drill. Fire up PC-HFDL right now, put it on a loud ground station, and leave it there until the system table is sent to an aircraft. It is done so in a special message type, and in 5 or 6 data packets. It is essential to receive all of these. After this happens, PC-HFDL will magically turn the numbers in the squitters back into frequencies.
The alternative is to get the new PCHFDL.DAT file online. An earlier post tells how to do this. Of course, since #47 has now gone the way of several others in the past weeks, that file has been removed from this column's web site. #48 will be posted whenever I get one that works.
Showing posts with label pc. Show all posts
Showing posts with label pc. Show all posts
Tuesday, November 08, 2011
Monday, July 26, 2010
Digital Mode Programs That Work #2: Multipsk
Multipsk is a multimode receive/transmit program that works with the PC sound card in Windows or Linux. It's rapidly becoming the big gun in freely available ham/SWL software for these platforms.
The program is by Patrick Lindecker, F6CTE. It can be downloaded from Patrick's F6CTE web site, which is in English. A Yahoo group (also in English) for users is reachable at Multipsk (at) yahoogroups.com. I haven't looked at this group, but I keep meaning to.
Just about everyone I can think of who uses Windows or Linux for serious utility work has at least tried this program. Now that SkySweeper is no longer supported, Multipsk is the most viable PC multimode package for under $3000 US. WAY under, in fact, since a perfectly acceptable version is available free. As in $0000 US. This is not crippleware or nagware. When you pony up the $45 (last I looked), you get more features, and lose the time limits on some others.
New versions come out on a regular basis, and most add at least one new mode. The latest is 4.18. The major change from 4.17 is the addition of US weather radio SAME (Specific Area Message Encoding) decode. I've played with SAME on my scanner a bit. Its purpose is to alert local areas for bad weather.
The list of other modes is boggling:
110A (MIL-STD-188-110A/B), 1382 (1200 baud MSK), STANAG 4285, VHF ACARS, ALE, AMTOR/SITOR, ASCII, BPSK/QPSK 32/63/125/250, CHIP 64/128, Contestia, Coquelet, CW (OOK/Coherent/FSK), DGPS, Domino, DSC, DTMF, FAX, Hellschreiber (Feld/PSK/FM), JT65, MFSK8/16, MT63, Olivia, Packet/APRS, Pactor-I (used mostly for calling), PAX, PSK10/63F/220F, PSKAM, QRSS, RTTY, SELCAL, SSTV, and THROB.
Whew.
Hams will be able to take advantage of many features for logging, radio control (with 3rd-party software), and display of things like maps. For utility, the later versions have steadily added "professional" modes, such as SITOR-A, non-amateur RTTY speeds and shifts, and a SYNOP decoder (time limited w/o registration). Now, if I could only get good skip on Hamburg Meteo when the SYNOP codes are on.
The package includes another program called Clock, which decodes the data hidden in most time signals and GPS. After registration, it can set your computer clock. I've used this on several low-frequency European time signals via the WebSDR in Holland. This is close to a worst case for decode, given the Internet link's general instability. With considerable patience, though, I've managed decodes on nearly all stations at one time or another.
Anything this complicated is going to have a learning curve. Also, many people have been intimidated at first by the user interface. Now, I have come to like this. It's way faster than going through menus or trying to remember presets when you're in a hurry to grab onto some signal. The downside, though, is that there really are a lot of little buttons.
The colors have also turned some people off, though I don't mind them at all. They help group the aforementioned little buttons in a fairly logical manner.
How do the decodes stack up against other programs? Most of the time, just fine. I like SkySweeper better for FAX, but a lot of people hate it. DGPS might be better than SkySweeper, though DSCdecoder beats them both. SIGMIRA is somewhat better than either for STANAG 4285, though that mode really pushes the edge for any sound card decoder.
Where Multipsk has the general edge, for me anyway, is its use as a tool for attacking completely weird signals. This is especially true for the PSK variants.
I realize that the high-end government packages are often pretty good at this. But they aren't free/ $45. Case closed.
The program is by Patrick Lindecker, F6CTE. It can be downloaded from Patrick's F6CTE web site, which is in English. A Yahoo group (also in English) for users is reachable at Multipsk (at) yahoogroups.com. I haven't looked at this group, but I keep meaning to.
Just about everyone I can think of who uses Windows or Linux for serious utility work has at least tried this program. Now that SkySweeper is no longer supported, Multipsk is the most viable PC multimode package for under $3000 US. WAY under, in fact, since a perfectly acceptable version is available free. As in $0000 US. This is not crippleware or nagware. When you pony up the $45 (last I looked), you get more features, and lose the time limits on some others.
New versions come out on a regular basis, and most add at least one new mode. The latest is 4.18. The major change from 4.17 is the addition of US weather radio SAME (Specific Area Message Encoding) decode. I've played with SAME on my scanner a bit. Its purpose is to alert local areas for bad weather.
The list of other modes is boggling:
110A (MIL-STD-188-110A/B), 1382 (1200 baud MSK), STANAG 4285, VHF ACARS, ALE, AMTOR/SITOR, ASCII, BPSK/QPSK 32/63/125/250, CHIP 64/128, Contestia, Coquelet, CW (OOK/Coherent/FSK), DGPS, Domino, DSC, DTMF, FAX, Hellschreiber (Feld/PSK/FM), JT65, MFSK8/16, MT63, Olivia, Packet/APRS, Pactor-I (used mostly for calling), PAX, PSK10/63F/220F, PSKAM, QRSS, RTTY, SELCAL, SSTV, and THROB.
Whew.
Hams will be able to take advantage of many features for logging, radio control (with 3rd-party software), and display of things like maps. For utility, the later versions have steadily added "professional" modes, such as SITOR-A, non-amateur RTTY speeds and shifts, and a SYNOP decoder (time limited w/o registration). Now, if I could only get good skip on Hamburg Meteo when the SYNOP codes are on.
The package includes another program called Clock, which decodes the data hidden in most time signals and GPS. After registration, it can set your computer clock. I've used this on several low-frequency European time signals via the WebSDR in Holland. This is close to a worst case for decode, given the Internet link's general instability. With considerable patience, though, I've managed decodes on nearly all stations at one time or another.
Anything this complicated is going to have a learning curve. Also, many people have been intimidated at first by the user interface. Now, I have come to like this. It's way faster than going through menus or trying to remember presets when you're in a hurry to grab onto some signal. The downside, though, is that there really are a lot of little buttons.
The colors have also turned some people off, though I don't mind them at all. They help group the aforementioned little buttons in a fairly logical manner.
How do the decodes stack up against other programs? Most of the time, just fine. I like SkySweeper better for FAX, but a lot of people hate it. DGPS might be better than SkySweeper, though DSCdecoder beats them both. SIGMIRA is somewhat better than either for STANAG 4285, though that mode really pushes the edge for any sound card decoder.
Where Multipsk has the general edge, for me anyway, is its use as a tool for attacking completely weird signals. This is especially true for the PSK variants.
I realize that the high-end government packages are often pretty good at this. But they aren't free/ $45. Case closed.
Monday, July 19, 2010
Digital Mode Programs That Work #1: DSCdecoder
DSC stands for Digital Selective Calling. It's an automated mode used with the Global Maritime Distress and Safety System (GMDSS). DSCdecoder is a small, sleek little utility which does exactly what its name promises. It decodes DSC calls, on all three bands (MF, HF, and VHF). These are output to the screen with the MMSI (Maritime Mobile Service Identity) of the calling and called station, plus the message type and any optionally transmitted data such as the reply frequency and mode. You can have the program search over the Internet for the MMSI and substitute it with the station/vessel name, if found.
DSCdecoder is good to just leave going and see what accumulates. DSC is not a busy mode, but it's a fun one to DX. This program does a really nice job of grabbing the real weak stuff.
There's more, though. This program also decodes Navtex (Navigational Telex) and Differential Global Positioning System (DGPS). It does a similarly bang-up job on these. It's the best one of several ham-level programs that I use.
Navtex is a Sitor-B service on three primary frequencies. These are 518 kHz (main freq, nearly always in English), 490 kHz (specific nations and languages, not used in the US), and the more lightly used HF frequency of 4209.5 kHz. The Sitor-B waveform is very close to DSC's (on HF), though other parameters are quite different. Therefore, the decoder performs well on it too. Those who like to tweak things, and who can tune accurately, can set up the advanced decoder. The improvement is slight, but definite.
Navtex stations take turns broadcasting schedules of short, highly formatted, maritime safety and weather messages, from different coastal locations. These rotations typically repeat several times a day, usually every 4 hours. Professional GMDSS equipment keeps a list of headers and typically only prints new messages. Most large vessels will have a Navtex printer somewhere on the bridge.
Navtex is useful for weather forecasts, and it's also fun to DX. Navtex stations are designed for specific local coverage areas, but at night they can propagate amazingly well for this type of station.
The extra dividend is that any Sitor-B decoder that can handle Navtex will work on most other transmissions in this mode. These are all over HF, coming from coast guards and meteo services worldwide.
DGPS is an interesting mode, using minimum-shift keying (MSK). It takes some tuning around in its low band to find strong stations. Fortunately, these are being implemented pretty much worldwide.
Stations use two different baud rates, identifiable from their bandwidth. DGPS decoders for our use turn its packetized data streams into lines of rather cryptic text data. I mostly use this for DXing, and I have checked off an amazing number of DGPS stations, considering that it is designed as anything but a DX mode.
Not many PC programs do DGPS. (Mac users are lucky. They have MultiMode, an excellent program.) Two that do are this one and the no longer supported SkySweeper. I've run them side by side, and most of the time DSCdecoder has successfully recovered more packets.
DSCDecoder is available from www.coaa.uk. The first 21 days are free, so you can try it out, get over a bit of a learning curve, and see if it's for you. After that, it's 25 Euros (a little over 32 bucks at today's exchange).
DSCdecoder is good to just leave going and see what accumulates. DSC is not a busy mode, but it's a fun one to DX. This program does a really nice job of grabbing the real weak stuff.
There's more, though. This program also decodes Navtex (Navigational Telex) and Differential Global Positioning System (DGPS). It does a similarly bang-up job on these. It's the best one of several ham-level programs that I use.
Navtex is a Sitor-B service on three primary frequencies. These are 518 kHz (main freq, nearly always in English), 490 kHz (specific nations and languages, not used in the US), and the more lightly used HF frequency of 4209.5 kHz. The Sitor-B waveform is very close to DSC's (on HF), though other parameters are quite different. Therefore, the decoder performs well on it too. Those who like to tweak things, and who can tune accurately, can set up the advanced decoder. The improvement is slight, but definite.
Navtex stations take turns broadcasting schedules of short, highly formatted, maritime safety and weather messages, from different coastal locations. These rotations typically repeat several times a day, usually every 4 hours. Professional GMDSS equipment keeps a list of headers and typically only prints new messages. Most large vessels will have a Navtex printer somewhere on the bridge.
Navtex is useful for weather forecasts, and it's also fun to DX. Navtex stations are designed for specific local coverage areas, but at night they can propagate amazingly well for this type of station.
The extra dividend is that any Sitor-B decoder that can handle Navtex will work on most other transmissions in this mode. These are all over HF, coming from coast guards and meteo services worldwide.
DGPS is an interesting mode, using minimum-shift keying (MSK). It takes some tuning around in its low band to find strong stations. Fortunately, these are being implemented pretty much worldwide.
Stations use two different baud rates, identifiable from their bandwidth. DGPS decoders for our use turn its packetized data streams into lines of rather cryptic text data. I mostly use this for DXing, and I have checked off an amazing number of DGPS stations, considering that it is designed as anything but a DX mode.
Not many PC programs do DGPS. (Mac users are lucky. They have MultiMode, an excellent program.) Two that do are this one and the no longer supported SkySweeper. I've run them side by side, and most of the time DSCdecoder has successfully recovered more packets.
DSCDecoder is available from www.coaa.uk. The first 21 days are free, so you can try it out, get over a bit of a learning curve, and see if it's for you. After that, it's 25 Euros (a little over 32 bucks at today's exchange).
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