VOA Radiogram Image & Harmonic Testing for 11/30 - 12/1

Sorry for late posting on this.

From Kim Elliott:

Hello friends,

Have your lab coats ready, because VOA Radiogram for the weekend of 30 November and 1 December will full of experiments.

The first experiment has to do with last weekend's slanted MFSK images. On Saturday, all listeners experienced badly slanted MFSK images. Merkouris, SV2HWM, in Greece quickly offered a solution by adjusting the sound card offset in Fldigi. I emailed this information to the group. Based on your responses, we agreed that a correction of -2250 ppm (parts per million), give or take depending on your sound card, produced the best results.

I still don't know what caused the slant, but if a correction of -2250 ppm was necessary, this indicates that something on the VOA side was 0.225% too fast. This discrepancy in speed did not affect the decoding of the text, only the MFSK images.

This weekend we will begin the program with an image of a single vertical blue line, transmitted three times for a total of 2 minutes, 15 seconds:

In Fldigi, open this box: Configure > Sound Card > Settings. Set the RX Corrections to 0 (zero) or to whatever setting you use normally. As the vertical line is transmitted, if it is not vertical, try a different ppm setting, then click Save. Repeat this process until you have a vertical line.   

If the calibration is as bad as it was last week, with the top of the line slanting to the right like the image below, you will need another correction of -2250 (minus 2250) ppm, more or less:



If the slant to the right is less severe, as below, a correction of -1000 ppm should work:



If the top of the line slants to the left, as below, try a correction of 1000 (positive 1000) ppm:




Audio Harmonics

Our second experiment involves the audio harmonics that many of you have noticed during VOA Radiogram broadcasts. They are sometimes noticeable on the Fldigi waterfall. For example, in the image below, the MFSK32 fundamental is from 1250 to 1750 Hz, with the bottom half of the second audio harmonic visible starting at 2500 Hz. It is actually from 2500 to 3500 Hz:



The transmitter in North Carolina is operating according to specifications, but there will always be some degree of audio harmonics. They are more noticeable with the digital text modes because the fundamental RF is very fixed between two frequencies, rather than diffused over a wide range as in voice transmissions.

The audio harmonics generally do not seem to impair the decoding of the text modes. For example, MFSK64 with our typical center frequency of 1500 Hz extends from 1000 to 2000 Hz, with the second harmonic safely out of the way from 2000 to 4000 Hz. Below is the MFSK64 as spectrally displayed on the University of Twente SDR receiver in the Netherlands. The fundamental in this double-sideband AM signal is 15668-15669 and 15671-15672 kHz, with second harmonics at 15666-15668 and 15672-15674 kHz:



Robert, KK5VD, in Alabama suggested this experiment: If we move the center frequency of MFSK64 to 1000 Hz, the fundamental will extend from 500 to 1500 Hz. The second harmonic will be from 1000 to 3000 Hz, so there will be an overlap. Will this have a negative effect on the decoding of the MFSK64?  We will investigate this question by transmitting the same VOA News story in MFSK64 centered on 1500 Hz, followed by the same story in MFSK64 centered on 1000 Hz.  We will repeat the experiment using the new long-interleave mode MFSK64L.

Here is the lineup for VOA Radiogram, program 35, 30 November/1 December 2013:

 1:37  MFSK16: Program preview (3:01)
 4:43  MFSK32: Slant test with 4 images (5:18)
10:03  MFSK32: Introduction to audio harmonic experiments (2:32)
12:33  MFSK64 1500Hz/1000Hz: Philippines radio (3:56)
16:27  MFSK64 1000Hz: W7VOA image (1:55)
18:24  MFSK32: Email address and intro to MFSK64L tests (:44)
19:08  MFSK64L 1500Hz/1000Hz: Ivanpah solar power station (5:30)
24:39  MFSK32: Image of Ivanpah facility (2:37)
27:13  MFSK32: Closing announcements (:32)
27:46  MFSK32: VOA Radiogram logo (:36)

Please send reception reports to radiogram@voanews.com

VOA Radiogram transmission schedule
(all days and times UTC)
Sat 1600-1630 17860 kHz
Sun 0230-0300 5745 kHz
Sun 1300-1330 6095 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina.

Thanks to all of you who sent reception reports for last weekend's VOA Radiogram. I will begin answering those reports today, as I digest Thanksgiving dinner.

I look for forward to hearing from you this weekend.

Kim

Kim Andrew Elliott
Producer and Presenter
VOA Radiogram

voaradiogram.net

Digital Digest Available as E-books

From Mike Chace-Ortiz, former Digital Digest editor of the late great Monitoring Times:

Fellow utility listeners

With the recent passing of Monitoring Times magazine, I have started publication of back issues of my "Digital Digest" columns as Amazon Kindle ebooks. These can be read on just about every desktop and mobile platform. Each annual compilation contains all 12 columns from a year together with links to software used, screenshots, audio clips and other reference material, and runs to around 50 pages in total.

For 15 years, Digital Digest covered various utility topics including embassies, military, peacekeeping, commercial, humanitarian and other organisations using digital communications on HF radio together with details about their operating habits, frequencies used, message formats and details about how to identify and decode their traffic.

The 2013 and 2012 editions are available by following these links:

http://www.amazon.com/Digital-Digest-2013-Mike-Chace-Ortiz-ebook/dp/B00GW4M9XY

http://www.amazon.com/Digital-Digest-2012-Mike-Chace-Ortiz-ebook/dp/B00GW545TY

Volumes from 2011 to 2000 will be available over the next few weeks.

The column itself will continue to be published by The Spectrum Monitor, the new magazine following on from Monitoring Times.

73

—mco

AB1TZ/G6DHU

It's Not You -- VOA Images Sent Slanted

The VOA Radiogram images for November 23 and 24 were sent at a speed considerably different from that in the original program.  Kim Elliott does not know the cause of the problem yet, but everyone's receiving them that way.  It's not you.

He has several ideas on how to get an accurate copy:

Merkouris Gogos in Greece sent correct images, but this is what he wrote:

"The +180 ppm sample rate correction value, which was working for months, had to be changed to -2080 ppm!"

I tried the same from my recording of reception via the University of Twente SDR receiver, and had to set the ppm correction to -2400 ppm.

For reception the rest of this weekend, I would recommend that you start with Merkouris's parameters.  In Fldigi: Configure > Sound Card  > Settings > under Corrections set the RX ppm to -2080. 

If you can record the broadcast, then decode from the recording, you can try various corrections to see what provides you with the straightest images.

Since the last broadcast is just now airing at time of publication, it may be too late to get a recording. Worry not:

If you want to decode from the "studio" recording of this weekend's broadcast:

soundcloud.com/voaradiogram/voar34

But set the RX ppm back to 0 (zero), because the recording seems to be OK.

Other people have tried changing audio playback speeds (if you can do that).  Otherwise, the correction in Fldigi is different for every setup, and seems to be somewhere around -2000 to -2100.  (Kim's -2400 probably had to do with latency in the remote Internet receiver.)

It might be worth checking http://voaradiogram.net/ to see how others are doing.

Thanks to Kim Andrew Elliott at VOA for this information.

------------------------

UPDATE: The images displayed properly here with a correction of -2340 ppm. This is using the WiNRADiO Excalibur Pro with Virtual Sound Card.

VOA Radiogram for November 23-24

From Kim Elliott:

Hello friends,

On VOA Radiogram during the past weekend, we had very good success with the decoding of the Chinese text, in both the MFSK32 and 64. Chinese text as an MFSK64 image was less successful, and it took longer to transmit. MFSK images are nice, but it is MFSK text that gets through in difficult reception conditions.

This weekend, our non-Latin alphabet will be Russian. In Fldigi: Configure > Colors & Fonts > use the pull-down menu, perhaps now set to ASCII, to select the UTF-8 character set.

There will also be several images and another comparison of the MFSK128 and MFSK128L (long interleave) modes.

Here is the lineup for the VOA Radiogram, 23-24 November 2013 (the left column shows the amount of time into the show, while the duration of each item is in parentheses):

 1:39  MFSK16: Program preview (now) (3:07)
 4:50  MFSK32: Milky Way evolution, with image (4:52)
 9:41  MFSK32: Russian text sample* (2:11)
11:54  MFSK64: Russian text sample* and image (1:49)
13:39  MFSK64/Flmsg**: Aquaponics, with image (5:17)
19:11  MFSK32: Email address (:43)
19:55  MFSK128: High school cubesat (1:18)
21:14  MFSK128L: High school cubesat (1:39)
22:55  MFSK32: Image of satellite (2:04)
24:58  MFSK32: Closing announcements (:34)
25:30  MFSK32: Some extras...

Please send reception reports to radiogram@voanews.com.

Screenshots are audio samples are also appreciated. Audio of VOA Radiogram received during challenging shortwave conditions is especially helpful. Audio in mp3 format is OK.

Thanks for your reports from the past weekend. I have begun responding to them.

I look forward to your emails this weekend.

Kim

Kim Andrew Elliott
Producer and Presenter
VOA Radiogram
voaradiogram.net

VOA Radiogram transmission schedule
(all days and times UTC)
Sat 1600-1630 17860 kHz
Sun 0230-0300 5745 kHz
Sun 1300-1330 6095 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina.

Recent Low-VHF Skip Heard in Southern California

With the calendar saying November, and the daily solar fluxes in the 163-176 range, it's THAT time again.

33 MHz fire departments are still active when the band opens, though there are fewer stations on every year.  The typical path heard on the West Coast is transcontinental, from the eastern US. There was also once a cable TV company in Agana, Guam which could be heard in the US in local afternoons, but that hasn't been reported in eons.

I'll be days going through SDR recordings.  Some early identifications are:

MHz
33.68  Tone call testing and ID "Malta-McConnelsville," "KBH343"  2258
-This is Morgan County Fire Dispatch, Ohio. Tac is on 33.86, also heard

33.70  So far two agencies:
-"Westmoreland" (Westmoreland County Emerg Mgmt,  KGH706 , Jeannette, PA)
-"Somerset" (Somerset County, PA, KGD869). "North-1" is 33.84, also heard. 

33.84  Somerset County, PA, "North-1" tactical frequency, unit wkg Somerset Command

33.86 So far two agencies:
-Licking County 911, Ohio, KQH904, lots dispatches Hanover engine (802) and medic (802)
-Malta-McConnelsville, tactical, ID given as "KBH343 at 1800 hours" (2300 UTC)

A Day In the Life of 10 Meters

Actually two days. November 13 and 14 were sorted together. Also, although the times are UTC, they are sorted by local time (PST).

All hits are JT65 on a dial/window frequency of 28076 kHz.  With its short exchanges and low information rate, JT65 is a good weak signal DX mode.  Perfect for 10 meters when skip allows, since it becomes a good low-power DX band.

Countries were looked up in the book.

Note the directional shift corresponding with time of day.  This is typical for long-range F2 propagation on frequencies this high. It follows the sun. Here in California, the day starts with Europe and Africa. It shifts to the Pacific in the afternoon, before ending with a pipeline to Japan.

South America tends to be in all day long. There are various reasons for this. Daylight is strongest over this path.  Buenos Aires, Uruguay, and tiny parts of Chile and Brazil are especially favored, because they lie on a geomagnetic latitude similar to SoCal. This facilitates transequatorial spread-F propagation. In these band conditions, the area is a guaranteed hit well into low VHF.

Here's the log. "dB" are relative to the noise over a 2 kHz audio passband, and the figure is nearly always negative.

UTC    dB     Exchange                                 Country

1728    -23    K AB0V EA1YV -18                 Spain

1731    -4      B CQ VA7JH CO70                  BC, Canada

1738    -26    K CQ EA8/RW3DO                  Spain

1746    -24    K CQ LU4XPE FD55                Argentina

1748    -4      B W9MO FG5FU FK96            French Guadeloupe Island

1756    -19    K CQ CX8AF GF15                  Uruguay

1806    -6      B KG6Q YV4GJN FK50           Venezuela

1814    -24    K WA0AM ZS1AGF RRR        South Africa

1913    -19    B CQ LU1WBM FE77              Argentina

2058    -13    B CQ LU8EX GF05                  Argentina

2132    -10    B CQ PY3AGI GG30                Brazil

2134    -18    K CQ CA3SOC FF46                Chile

2152    -16    B CQ JA3GAK PM74               Japan

2152    -14    B CQ CE6MBK FF30               Chile

2212    -11    B CQ LU2BN GF05                  Argentina

2217    -13    B VA3DAZ JA3GAK 73           Japan

2217    -27    K NY7U JA3CG PM95             Japan

2217    -21    K CQ JA1LZB PM95                Japan

2218    -20    K JA2HMD PY2HJ GG66        Brazil

2222    -25    K NQ6Y JA3BLK R-11            Japan

2223    -21    B CQ JA2HMD PM95              Japan

2228    -12    B CQ LU2DO GF05                  Argentina

2231    -17    K CX8AF JA1IZ PM95             Japan

2232    -20    K CQ JG1PDG PM96                Japan

2234    -14    B CQ LU8EX GF05                  Argentina

2239    -20    K K8QZ LU6XQB R-20            Argentina

2240    -23    K KA4IUO JA3FQO 73            Japan

2240    -20    B CQ JH4BTI PM54                 Japan

2247    -21    K AE7CD JG6CDH PM43        Japan

2249    -22    K CX8AF VA3DAZ EN82        ONT, Canada

2250    -24    K CQ PY2TWI GG66                Brazil

2254    -15    B CQ CE6MBK FF30               Chile

2255    -19    B PY2TWI JA1VGV QM06      Japan

2256    -24    K CQ VK6IR OF77                   Australia

2257    -26    K CQ BD7OXR OL62               China

2258    -20    B NU6O JH1KYA                     Japan

2259    -19    B CQ JA1KXQ PM95               Japan

2309    -23    K N4EMP JQ2SGN PM94        Japan

2310    -16    K AB4EG JA1PVX PM95        Japan

2314    -23    K WA4MIT JH3OWW             Japan

2323    -19    B CQ JA6VZ QM06                  Japan

2325    -22    K CQ JG1ERW PM95               Japan

2325    -19    B NK0G JA3FQO PM74           Japan

2325    -21    K K5AGC JA1NUX PM95       Japan

2327    -16    B K0JV JA2HMD PM95           Japan

2330    -20    K CQ JG1PDG PM96                Japan

2331    -23    K VE7LGX JA2HMD               Japan

2332    -16    B CQ LU4ECN GF12                Argentina

2333    -21    K JH3OWW LU8VB FF60       Argentina

2333    -24    K K5AGC JH1QKG                  Japan

2339    -14    B LU4ECN JO3TAP PM74       Japan

2340    -21    K LU8VB JA6QV                     Japan

2341    -13    B LU4ECN JA1VGV QM06     Japan

2344    -19    K AF6JO JR3QFB PM74          Japan

2346    -24    K CQ JG1PDG PM96                Japan

2347    -17    B CQ JA1PVX PM95                Japan

2352    -24    K CQ CX8AF GF15                  Uruguay

2353    -21    B JA6VZ LU8AFR GF05          Argentina

2355    -20    K W7ZWW JA1MOD 73          Japan

2355    -25    K CQ JA6ADA PM52               Japan

2356    -12    B CQ JA6QV PM53                  Japan

2357    -16    B K5AGC JG6CDH PM43        Japan

2359    -19    K CQ LU2BN GF05                  Argentina

0000    -7      B VK4BDJ JH3OWW PM74    Japan

0000    -12    B 25W VRT58 73                      ?

0000    -22    K LU2BN JA1NUX PM95        Japan

0003    -25    K CQ JA1MOD PM96              Japan

0004    -18    K CQ CX5BL GF15                  Uruguay

0004    -20    B CQ JA7DQF QM07               Japan

0005    -9      B NS6E JF8EPR QN03             Japan

0008    -15    B JA2DMT TU 73                     Japan

0012    -24    K W6GPM JA1MOD 73           Japan

VOA Radiogram for the weekend of 16-17 November 2013

Last week's VOA Radiogram was interesting.  On the higher frequencies, copy of the long-interleave MFSK and the Thor100 was good.  On the lower ones, which had better signal strength but also more noise, they produced gibberish, and 8-bit UTF-8 gibberish at that.  Same location, receiver, software, and antenna for both, of course.

This week looks interesting again.

From Kim Elliott:

Hello friends,

When we last transmitted Chinese characters on VOA Radiogram, we noted that they printed out more slowly than English letters. This is no doubt due to the greater complexity of the code involved with non-Latin alphabets. This weekend we will transmit Chinese characters in MFSK32, then try to speed it up with MFSk64. Make sure you have Fldigi set to the UTF-8 character set.

We will also continue our experiments with the new long-interleave modes MFSK64L and MFSK128L.

Here is the lineup for VOA Radiogram, 16-17 November 2013 (produced using Fldigi 3.21.77 and Flmsg 1.1.33, both available from w1hkj.com):

NEW: Left column shows time into the program. In parentheses is the duration of each item…

1:38   MFSK16: Program preview (3:06)

4:45   MFSK32/64: Chinese text sample (2:34)

7:19   MFSK64 image: Chinese text sample (1:55)

9:14   MFSK64/64L: Moon craters (5:46)

15:00  MFSK32: E-mail address (:43)

15:43  MFSK128/128L: European GOCE satellite (2:46)

18:29  MFSK32/64: Image of GOCE satellite (3:43)

22:12  MFSK64/Flmsg: Energy from microwaves (2:51)

25:03  MFSK32 image: Metamaterial array (2:01)

27:04  MFSK32: Closing announcements (:33)

There will be a few "extras" at the end of the show.

Please send reception reports to radiogram@voanews.com

I am now answering your emails from the past weekend.

I hope you can tune in and write in this weekend.

Kim

Kim Andrew Elliott

Producer and Presenter

VOA Radiogram

radiogram@voanews.com

http://voaradiogram.net

Twitter: @voaradiogram

VOA Radiogram transmission schedule
(all days and times UTC)
Sat 1600-1630 17860 kHz
Sun 0230-0300 5745 kHz
Sun 1300-1330 6095 kHz
Sun 1930-2000 15670 kHz
All via the Edward R. Murrow transmitting station in North Carolina.

Last Monitoring Times Issue is Published

The electronic edition just came out, and it looks good.  The print edition should be around any day now.

Lots of farewells, including one from the Groves.

Utility World is dead.  Long live Utility Planet.

Weak VHF Skip November 8

Freq   UTC   Tone   Traffic/Comments

33.70  2200  107.2  DTMF *2222, later 6581
33.70  2216   None  "Westmoreland" clg ???
33.78  2147   82.5  carrier only
33.82  2138  141.3  tone calls
33.86  2141   82.5  EMT call in central time zone
33.86  2149   77.0  YL, weak
33.98  2156  103.5  carrier only

All reception by editor in Southern California, using a WiNRADiO G33DDC with 45' PAR EF-SWL antenna.

Westmoreland (33.7) is Westmoreland County Emergency Management, PA.

Interesting VOA Radiogram for November 9 & 10

VOA Radiogram continues its developmental mode with the Fldigi developers.  This will include a transmission of the new Thor100 plus more comparisons between long-interleave MFSK and the short-interleave version that's standard on VOA Radiogram. This will require another update to the Fldigi software, available at w1hkj.com .

Don't forget the new local times in the US after "falling back" last Sunday.

From Kim Elliott:

Hello friends,

VOA Radiogram during the weekend on 9-10 November 2013, will be a bit different. In addition to the usual MFSK modes, we will transmit Thor100. This is at the request of one of the Fldigi developers, who needs some actual (not simulated) shortwave reception of Thor100 for his testing.

We will continue our comparisons of the new long-interleave modes MFSK64L and MFSK128L with their short counterparts.

All of the modes to be broadcast this weekend are available in the latest version of Fldigi: 3.21.77, available from w1hkj.com.

Here is the lineup of modes for VOA Radiogram, program 32, 9-10 November 2013:

2:55  MFSK16: Program preview

4:35  MFSK32: Radio France International memorial and logo

1:30  MFSK64: VOA News re SR-32 airplane

1:53  MFSK64L: Same VOA News story

3:36  MFSK32/64: Artist's conception of SR-32  

 :38  MFSK32: E-mail address

2:17  Thor100: VOA News re earth-sized planets

1:48  MFSK128: Same VOA News story

2:10  MFSK128L: Same VOA News story

1:44  MFSK32 image: Artist's conception of planet Kepler 78b

1:48  MFSK32: Closing announcements/VOA Radiogram logo (500x44)

There will also be some surprises at the end of the show.

Please send reception reports to radiogram@voanews.com. If possible,  audio samples and screenshots are also appreciated.

I will be answering your e-mails from last weekend (2-3 November) starting today.

I look forward to hearing from you this weekend.

Kim

Kim Andrew Elliott

Producer and Presenter

VOA Radiogram

voaradiogram.net

VOA Radiogram transmission schedule

(all days and times UTC)

Sat 1600-1630 17860 kHz

Sun 0230-0300 5745 kHz

Sun 1300-1330 6095 kHz

Sun 1930-2000 15670 kHz

All via the Edward R. Murrow transmitting station in North Carolina.