Friday, May 31, 2013

More Images this Week on VOA Radiogram

On VOA Radiogram for the weekend of 1 and 2 June 2013, we will continue to compare MFSK32 and EasyPal images. Here is the lineup for the program:

3:44    MFSK16: Program preview
3:17    MFSK32: VOA News story about Olympics wrestling
3:16    MFSK32: VOA News story about 2013 hurricane season
1:10    MFSK32: File image of Atlantic hurricane
2:53    MFSK32: VOA News story about colliding galaxies
1:04    MFSK32: Image of the colliding galaxies
1:21    MFSK32: Introduction to MFSK64 and EasyPal
1:30    MFSK64: Same VOA News story about colliding galaxies
 :39     EasyPal text: Same VOA News story about galaxies
2:38    EasyPal image: Colliding galaxies
2:38    EasyPal image: Soyuz capsule being moved to launch site
1:09    MFSK16 closing announcements
 :29     Surprise mode of the week

To decode EasyPal text and images, download the 4-May-2013 version of the program from vk4aes.com.

To decode the MFSK modes, use Fldigi from w1hkj.com or another digital decoding program.
 
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.

Please send reception reports to radiogram@voanews.com

And visit voaradiogram.net (where any schedule or frequency changes will be posted)

Twitter: @VOARadiogram


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Some successful decodes of the EasyPAL images were made. These, of course, look great, since it's either all or nothing.

Friday, May 24, 2013

It's Image Week on VOA Radiogram

Hello friends,

Thanks to everyone who sent reception reports, audio samples, screenshots, etc., from last weekend's VOA Radiogram. The SSTV modes have performed well but, according to most your reports, MFSK32 images provide better images.

On VOA Radiogram the weekend of May 25-26, we will continue our experiments with images via shortwave broadcast. The MFSK32 and SSTV modes are analog. Now we will try purely digital images using EasyPal software.

Download EasyPal from vk4aes.com. After EasyPal is installed, go to Setup > Setup c/s-soundcard-PTT > Soundcard and select the soundcard you use to receive VOA Radiogram.

In EasyPal, click the RX button to receive images. You should see a waterfall along the left side of the interface. The software will indicate how many segments have been received. Unlike SSTV and MFSK32 images, you will not see the picture slowly form on the software interface. Instead, when a sufficient number of segments has been received, the picture will appear instantaneously.

Will EasyPal work in a shortwave broadcast environment? I have no idea, but it's worth trying.

Here is the lineup for today's program:

MFSK16: Opening announcements (now)

MFSK32: VOA news story about the comet ISON (4:07)

MFSK32: NASA image of the comet ISON (1:03)

MFSK32: VOA news story about new train lines in South Korea
(3:22)

MFSK32: Image of the South Korean train (3:57)

MFSK16: Introduction to EasyPal (1:06)

EasyPal: Same image of the South Korean train (2:38)

EasyPal: Image of the cicada (large insect) transmitted last week
in SSTV and MFSK32 (2:44)

EasyPal: Text (:19)

MFSK16: Closing announcements (1:09)

Surprise mode of the week (:27)

Please send reception reports to radiogram@voanews.com

I hope you can tune in and decode this weekend.

Kim Andrew Elliott


VOA Radiogram
radiogram@voanews.com
Twitter: @voaradiogram

This ought to be interesting. The EasyPAL waveform resembles HamDRM, and was intended for amateur single-sideband equipment. What it'll do on an AM transmitter is anyone's guess.  -Hugh

Saturday, May 18, 2013

Additions/ Corrections to Weekend Digital SWBC Schedule

1. The P5 SSTV mode will decode in MMSSTV.

2. The higher frequency given for Radio Australia at 1230 UTC is in error.  It is probably definitely 12065 kHz.  The stated 12095 kHz is not an R. Australia frequency, and in fact it is used by a Philippine broadcaster at this time.  The western US should have absolutely no trouble copying the 11945 broadcast at 0830.

3. Copy of the text modes was around 90% here in California for the first VOA Radiogram transmission. The only issue was deeper than usual fading, possibly left over from last night's CME/auroral event.  The SSTV was noisy, but then SSTV usually is on anything less than an optimum channel. The "surprise" mode came through just fine, though I won't spoil the surprise.

[Update: 100% copy on 5 MHz.]

4. We thank Kim Elliott for doing this every week.

Friday, May 17, 2013

Big Weekend for Digital SWBC Trials

VOA Radiogram:

More SSTV on VOA Radiogram May 18 and 19

On VOA Radiogram for the weekend on 18 and 19 May, we will continue to experiment with images. In fact, we will transmit the same picture three ways: in two SSTV modes and then as an MFSK32 image. Bring something to read, or an electronics project, because these picture transmissions will take 4 to 5 minutes each.

To decode the SSTV modes, several software programs are available. They include the RX-SSTV (receive only) from http://users.belgacom.net/hamradio/rxsstv.htm , MMSSTV from http://hamsoft.ca/pages/mmsstv.php , and Digital Master 780, part of the Ham Radio Deluxe suite, from http://www.hrdsoftwarellc.com .

Before the images will be two VOA news stories in MFSK32 text, with the usual center audio frequency of 1500 Hz. The second story is in French, as we continue to determine if accented letters appear correctly on your display.

To view accented characters in Fldigi: Configure > Colors & Fonts > next to Select Char Set, select UTF-8. To keep your selection of UTF-8, under Configuration, click Save Config.  

Here is the lineup for VOA Radiogram the weekend on 18 and 19 May:

2:55        MFSK16 Program preview
1:59        MFSK32 VOA News in English
4:03        MFSK32 VOA News in French
1:07        MFSK16 Intro to SSTV transmissions
4:31        Scottie DX SSTV
 :10        Tone (to give you time to save your Scottie DX image)
5:08        Pasokon P5 SSTV
 :25        MFSK16 intro to MFSK32 image
4:07        MFSK32 image
1:10        MFSK16 closing announcements
1:22        Surprise mode of the week (mixes somewhat with the closing music)      
                             
On VOA Radiogram during the weekend of 25-26 May, we will experiment with the Easypal digital SSTV mode, comparing it to MFSK32. Please download Easypal from http://vk4aes.com . Easypal images are transmitted by radio amateurs on 14233 kHz.

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.

Pasokon P5 is an old mode.  I have no way of determining if it's one of MMSSTV's several undocumented modes.  [UPDATE 5/18: MMSSTV does do it, and it works well.]   -Hugh


The Mighty KBC

More Hell this weekend on The Mighty KBC


The Mighty KBC will transmit the Hell 80 mode at about 0133 UTC on Sunday 19 May (9:33 pm EDT Saturday), centered on 1500 Hz. This is during its North America broadcast Sunday at 0000-0200 UTC on 9925 kHz via Nauen, Germany.

At just before 0200 UTC, images in MFSK32 will be centered on 1000 and 2000 Hz.  

Hell is short for Hellschreiber, "Shiny Writing," an old CW based mode which synchronously prints letters onto paper tape or its various computer display emulations. Since darkness changes with signal strength, it's a "fuzzy" mode like analog fax.  This makes it possible to read the large double print even on sub-optimal channels. -Hugh


 Radio Australia:

Radio Australia digital text and image May 18 and 19

For the first time, Radio Australia will broadcast digital text and images. This will be Saturday 18 May and Sunday 19 May 2013.

UTC               Frequency (kHz)   Target

0830-0835      7410 & 11945        south-west Pacific

1230-1235      9580 & 12095 12065       south Pacific

As is characteristic of shortwave, reception outside the nominal target areas is likely.

Each five-minute broadcast will include:

  :34 RA tuning signal (still Waltzing Matilda?)
  :05 Tone 1500 Hz
1:42 MFSK16 text
1:42 MFSK32 text
  :55 MFSK32 image

All modes are centered on 1500 Hz

The Radio Australia digital transmissions can be received on any shortwave, even if it does not have single sideband capability. Patch audio from the radio to a personal computer, and use software to decode the modes. For more information, see how to decode the modes.

Monday, May 13, 2013

Bright X2.8 Solar Flare with R3 Blackouts at 1600 UTC

While X.2.8 is not a huge solar flare, it's a pretty respectable one, and one of the largest in the low Cycle 24.  This event occurred just over the sun's east limb and sunlit side HF radio propagation is only now starting to recover at 1642 UTC.

This comes after a flare in the X1 range last night (North American time).

Due to location on the sun, any CME should miss the Earth, or any other planet.



Friday, May 10, 2013


VOA Radiogram for May 11-12 will include SSTV

VOA Radiogram for the weekend of May 11 and 12 will feature long stretches of VOA News in plain text, using the MFSK 32 and 64 modes. No Flmsg or Flamp this time. This weekend’s program will also include our first test of slow scan television (SSTV).

Here is the lineup:

MFSK16 (2:28)     Preview

MFSK32 (12:08)     VOA News stories
The first of the three stories will be in Spanish. This is to determine how letters with accent marks appear on your display. The second VOA news story will be followed by an accompanying MFSK32 image
MFSK16     Intro to the next mode

MFSK64 (3:34)    VOA News story

MFSK16     Intro to the next mode

SSTV Scottie DX (4:31)
There are several software programs that decode SSTV, including Digital Master 780 (DM780) and MMSSTV. A free receive-only SSTV decoder is RX-SSTV from  users.belgacom.net/hamradio/rxsstv.htm
MFSK16 (1:11)     Closing announcements

Closing music, accompanied by the surprise mode of the week

Please send reception reports to radiogram@voanews.com

Screenshots and audio samples are welcome, especially audio of less than perfect reception conditions.

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.

Saturday, May 04, 2013

What A Difference A Week Makes on 5745 kHz

The venerable transmitter at the Edward R. Murrow Transmitting Center was a steady s9 + 10 dB in SoCal this week. SailMail was well behaved, as was the geomagnetic field despite recent flares.  It was the best signal ever, and so this test will have to be labelled as a high-quality transmission path.

Copy of the MFSK was 100% in all modes, with files saved in both Flmsg and Flamp.  The Flamp took all three passes, but got it.  If Kim wants to know what worked and what didn't, well, it all worked. 

There'll be more when everything's massaged.

Hurricane on Saturn (VOA Radiogram)

Friday, May 03, 2013

VOA Radiogram for May 4-5


VOA Radiogram for May 4-5: All MFSK, with another Flamp

In the next few weeks, we will be transmitting more MFSK32 and MFSK64, and comparing these two speeds of MFSK. MFSK64 (240 wpm) would allow us to put more information into a broadcast, but MFSK32 (120 wpm) would perform better in difficult reception conditions.

Last weekend, after using Flamp to transmit a VOA news story twice, some of you successfully received more than 90% but not quite 100% of the blocks. This weekend, we will use Flamp to broadcast a VOA news story three times. Please use Flamp 1.0.x.; the experimental version Flamp 2.0 is not compatible with Flamp as currently transmitted on VOA Radiogram.

The question for us is whether it makes sense to use Flamp (or similar future app) to transmit a news story two or three times using a fast mode like MFSK125, or just send the story once using a slower but more robust mode, like MFSK32 or MFSK64.
Here is the schedule of modes for the May 4-5 VOA Radiogram:

MFSK16: Program preview
MFSK32: Two VOA news stories
MFSK32: Image to accompany story to follow
MFSK32: VOA news story in Flmsg* format
MFSK64: Same VOA news story in Flmsg* format
MFSK128: Same VOA news story in Flamp* X3 format (compressed**)
MFSK16: Closing announcements
MFSK32: Image

An MFSK16 mode ID will precede each mode transmission.

All modes (except for one surprise mode) will be centered on 1500 Hz.

*Download Flmsg, Flamp 1.0.01, and Fldigi from www.w1hkj.com
**Because it is compressed, you will not see recognizable words during this Flamp transmission

Two interesting suggestions sent by listeners:

John Hoskins WA5NJG runs two instances in Fldigi during VOA Radiogram. One is set permanently to MFSK16 (no RSID) to receive the mode IDs. The other instance follows the modes being tested.

Ralph Wallio W0RPK suggests turning off Fldigi’s AFC during VOA Radiogram. This will help keep the audio frequency on 1500 Hz, rather than chasing a noise up or down in audio frequency as sometimes happens with the AFC on.

Please send reception reports to radiogram@voanews.com. Audio samples of digital text that is successfully decoded during difficult reception conditions are especially helpful.

And visit 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.
Wishing you good decoding whether reception is good or not,
Kim