Friday, August 09, 2013

VOA Radiogram for August 10-11: some interesting experiments

From Kim Andrew Elliott:

Hello friends,

I am in the process of answering your reception reports from the past weekend's VOA Radiogram.

Some of you are doing some interesting experiments with the digital modes on VOA Radiogram. And some of you are letting us know about some useful techniques to improve both the production and the reception of the program.

Mark, WA4KFZ, notes that the SSTV Denoiser software, part of the SSTV Tools suite from, can be effective with some of the "noisy" MFSK images you receive on VOA Radiogram.

In this weekend's VOA Radiogram, one VOA News item will be in the MFSK22 mode (80 words per minute). Unlike the MFSK 16, 32, and 64 modes, which have a sample rate of 8000 Hz, MFSK22 has a sample rate of 11025 Hz. For this weekend's program, I recorded to one track at 48000 Hz for the voice introduction and closing music, one track at 8000 Hz for MFSK 16 and 32, and one track at 11025 Hz for the MFSK22 item. Then all three were mixed to one .wav file with a sample rate of 48000 Hz.

Another "feature" in this weekend's program will be five seconds of silence whenever modes are changed. This might improve the performance of the RSID.

The Flmsg-formatted VOA News story in this weekend's program is 9 minutes, 6 seconds long. That might seem unusually long, but it includes 4 minutes, 20 seconds for a VOA logo in SVG format as part of the html. This was created for us by Mark Hirst in the UK.

Here is the lineup for VOA Radiogram, 10-11 August 2013:

2:30  MFSK16: Program preview
3:26  MFSK22: VOA News re import of Apple products
3:12  MFSK32: Greetings to l'Associazione Italiana Radioascolto
2:10  MFSK32 image: AIR logo
9:06  MFSK32/Flmsg*: VOA News re one year of Curiosity on Mars
2:26  MFSK32 image: Curiosity tire tracks
1:10  MFSK16: Closing announcements
2:20  Surprise image, text, image of the week

*To make Flmsg work with Fldigi (both can be downloaded from, in Flmsg: Configure > Misc > NBEMS -- Under Reception of flmsg files, check both boxes, and under that indicate where your Flmsg.exe file is located.

Please send your reception reports, audio samples, screenshots, comments, ideas, suggestions to .

Thanks for listening and decoding.


Kim Andrew Elliott
Producer and Presenter

VOA Radiogram
Twitter: @voaradiogram
Some magnetic storming is predicted for this weekend, so keep your fingers crossed and make an offering to the Propagation Gods.