I am sending this preview of program 304 (11-16 May 2023) a few days early to give you time to download, install, and practice decoding the EasyDRF we will be using.

EasyDRF is a version of HamDRM which can be decoded using software developed by Daz Man in Australia.

Program 304 is a repeat of Shortwave Radiogram 300, but in EasyDRF. Details of program 300 are here.

The EasyDRF software works in Windows and under Wine in Linux. See Daz’s downloading and operating instructions below.

The sound is different from MFSK. Easy DRF is more of a constant buzz. Shortly after the buzz starts, the file SWRG-300-00.html will  appear in the Rx Files subfolder. Open that html file and watch the images populate it, one by one, during the half hour – reception permitting!

If you want to practice decoding EasyDRF before actual radio reception, the audio file is available here:

https://storage.googleapis.com/dazman/misc/2023-05-06-EasyDRF_Radiogram-v06-ODC-EQ12.wav

Important: If you decode from the downloaded audio file, delete or move the files from the Rx Files subfolder before decoding from actual radio reception.

Questions about EasyDRF can be addressed to Daz via Twitter: @DazDude4000, or email: dazdude(at)hotmail.com

Here are Daz’s instructions to install and use EasyDRF:

This EasyDRF version of Shortwave Radiogram program 300 can only be decoded with the EasyDRF Windows application program.

SOFTWARE

Website: http://homepages.ihug.com.au/~daz2002/tech/EasyDRF/

Installation: Download the executable file from the GitHub release directory. Create a new folder on the PC hard drive named “EasyDRF”, and move the downloaded “EasyDRF.exe” file to it. That’s all. (Do not create the installation folder in “Downloads”, as this can cause security issues.)

AUDIO

Feed the audio into your PC the same way as for normal Radiogram broadcasts.

Options are: VB-Cable (SDRs), line input or microphone (analog radios).

NOTE: If using SDR# (SDRSharp), disable “antifading” as it can severely degrade data signals.

After installation into its own folder, start EasyDRF by double-clicking on the EasyDRF.exe file and select the correct input device in the Soundcard -> RX Input menu setting.

Check audio level using the Display -> Input Level menu setting. Adjust the receiver audio level to be near mid-scale on the Input Level graph. If the graph turns red, the level is too high.

Set the Waterfall display under Display -> Waterfall menu setting. Signals and noise from the receiver should appear on the waterfall display.

It’s a good idea to make a recording of the broadcast in case of decoding problems.

AM-Sync demodulation is recommended, to reduce carrier fade distortion that can severely degrade data decoding.

DISPLAY

This Shortwave Radiogram program consists of a series of files, sent using EasyDRF. The entire program is intended for web browser display, for easy viewing. The HTML file is sent first. When the HTML file saves, open a new web browser window. Click the “RxFiles” button on EasyDRF to open the file save folder, then drag and drop the “SWRG-300-00.html” file into the web browser to display it. (You can also right-click on the “SWRG-300-00.html” file, then “Open with” browser of choice.)

The HTML page will open, and it will display stats on the received files in the top right corner. The page can be browsed while the files are still decoding.

Please include the stats in your reports (a screenshot), as the image quality does not change with radio conditions.

The images will automatically load into the page as they progressively decode and save. Automatic image loading stops after image 12 is loaded, or after 30 minutes. Images are enhanced for display using a custom SVG filter.

In most cases, only 51% of good data is needed for each file, due to RS4 error correction. If any files fail to decode, some images will be missing from the page.

Thanks for decoding the Shortwave Radiogram program 300 EasyDRF special broadcast!

—-

Please send reception reports reports, as usual, to radiogram@verizon.net. Or report them to Twitter @SWRadiogram

Shortwave Radiogram Transmission Schedule

  UTC Day  | UTC Time      | Frequency        | Transmitter       |
|----------|---------------|------------------|-------------------|
| Thursday | 2330-2400 UTC | 9265 kHz         | WINB Pennsylvania |
| Friday   | 0530-0600 UTC | 7780 kHz         | WRMI Florida      |
| Friday   | 1300-1330 UTC | 15770 kHz        | WRMI Florida      |
| Friday   | 1400-1430 UTC | 15735 kHz DRM    | WINB Pennsylvania |
| Saturday | 0230-0300 UTC | 9265 kHz         | WINB Pennsylvania |
| Saturday | 2300-2330 UTC | 7570 kHz         | WRMI Florida      | 
| Monday   | 0800-0830 UTC | 5850 kHz         | WRMI Florida      |
| Tuesday  | 1430-1500 UTC | 9955 kHz         | WRMI Florida      |