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Decoding the SW Radiogram Broadcasts

From The RadioReference Wiki

Welcome to the Decoding the Shortwave Radiogram Broadcasts page. This page will help both newcomers as well as more experienced people with topics regarding decoding the digital broadcasts as advertised on the Shortwave Radiogram page. It's built in a Q&A style to make finding topics relevant to the user easier to find

What Kind of Radio Do I Need?

Just about any radio that covers the 2-30 Mhz range is capable of receiving these stations. It should be reasonably stable, selective and sensitive. This encompasses a wide range of radios, everything from portables, such as those from Tecsun and Degen, all the way to Software Defined Radios (SDR) such as the SDRPlay and Perseus. Even wide band radios like those from Icom and AOR can be used. It doesn't need to be expensive. To begin your research, see our HF Equipment and Accessories and Software Defined Radios articles.


What are some examples of portables used to receive the SWR broadcasts?

These are just a small sample of the portables reported to be used on the SWR Facebook and Twitter pages. There are numerous others, and the reader is encouraged to research these and other radios using the resources mentioned above.


I Dont Have A Radio Yet. Can I Use a Web Radio?

Yes you can. If you don't have the Stereo Mix app on your PC, you will need to install software like Stereo Mix Plus to route the audio from your speakers to the soundcard. You can find some online networks in our Live Tunable Receivers article. See the topic below about routing audio to your PC for a lot more on this subject.


What About Antennas?

It's been often said that the better the antenna, the better your results. Unfortunately sometimes that is difficult to obtain; you may be in a situation where outdoor antennas are not allowed, or you have very little space with which to work. What radio you are using, your budget and circumstances will play a large role in what you can use. Read our Basic HF Antennas article for a discussion on this topic.


How Can I Get a Better Signal?

If you have done as much as you can with your radio and antenna, but are still not satisfied with your results, there may be some more than you can do to improve your chances. See our Improving HF Reception for a discussion on this topic.


Where Can I Get the Schedule and Frequencies?

Take a look at the Shortwave Radiogram website. This is where the program for the week, along with the schedules and frequencies are posted. They are also repeated on mailing lists such as World of Radio (WoR) on groups.io


How Does the Signal Get to Me, Anyway?

We are very much at the mercy of the Sun when it comes to how signals get propagated across the globe. Unfortunately, as of this writing, we are in a very low period of solar activity, so we must depend on better radios and antennas to help. However, an understanding of how a signal propagates through the ionosphere is very important; this will help you to understand why a signal can be heard at some times but not others. See the AE4RV Propoagation Primer for a basic discussion on this topic. Be sure to turn your flash player on before looking at this site.


I Understand You Can Use an Android Device to Decode the Broadcasts?

Yes, the application is called TIVAR. To learn where to get it, and see how to use it, please see the Decoding the SW Radiogram Broadcasts with TIVAR article Also see a new application called AndFLMsg. Most of what is written in the above article will apply here


How Do I Get the Audio From My Radio (or SDR) To The PC?

This is a topic that is difficult to define simply, as there are so many possible ways to connect the two together. The method used for connecting a portable radio or desktop is very different how you would connect a Software Defined Radio (SDR). See the Connecting Radios to Soundcards article for an extensive discussion on this topic.

SDR Information


What is this DRM listed on the WINB schedule? Can I Tune This or Decode it?

DRM stands for Digital Radio Mondiale, a method of increasing the fidelity of a HF signal. Most any desktop or portable radio will need a special modification to be able to decode this; SDRs will need software. It will otherwise sound like a loud hash. See our DRM article for more information on this mode.


What Modes Are Being Used?

There are literally hundreds of different modems being used on the HF spectrum. Here, we are concerned with modes that are used in the amateur radio (ham) community, as software for these modes is readily available.

From the Signal Identification Wiki


Other Sources


Where Can I Find Compatible Software to Copy These Broadcasts?

While FLDigi is the most popular software used for this, it's not the only one that's capable of decoding these broadcasts. All of these applications recognize the use of the RSID to aid in recognizing the mode that is being sent. Questions or issues with the software should be directed to the indicated mailing lists, where specific help is available.


How do I configure the RSID feature to work with the SW Radiogram Broadcasts?

  • First a little background information; while the RSID is sent at an audio frequency of 1500 hz, there is a 1000 Hz tone start up tone that might confuse the decoders. This could be one reason why if you set this up to record automatically, you might not get a decode.


DM780 (Ham Radio Deluxe)


FLDigi
  • You can get to the setting using Config then select Config Dialog. Then in the menu, select IDs then RsID.
  • Apply the settings found in Figure 1,
  • Next, Go to Misc then Sweet Spot. Make sure the Always Start button is turned off (Figure 2). Note that if you also use FLDigi for transmitting, you will need to come back here to turn it back on. Be sure to hit Save then Close when done.
  • If you wish to use Notifications, see the settings in Figure 3.
  • When you are done making changes go back to the main screen, select Config then Save config. If you fail to do this, the changes will be lost when you close the session.

  • Figure 1

  • Figure 2

  • Figure 3


MultiPSK
MultiPSK RSID
  • The screen shot is accessed from the RX/TX screen. See Configuration / Management of the identifiers.
  • Set Detection Mode to Continuous and set Modes to All
  • Download The_RS_ID_easy_with_Multipsk (a Word .doc file) from the MultiPSK website
  • Also see the Digital Mode Identifiers (YouTube video)


How do I decode the signal when the center frequency drops to a very low level (i.e. 65 hz)?

  • Most soundcards won't go down below 200 Hz or so. To get around this, you must use a sideband capable radio or a SDR. Listen in either USB (preferable) or LSB. On LSB you must tune 1 kHz higher. On USB you must tune 1 khz lower. Because AM signals have two sidebands, the 65 Hz signal then becomes 1065 Hz and 935 Hz, and the AM carrier becomes 1000 Hz (which is the amount by which you offset your tuning), which you will also hear. So you will actually get three signals, the 1065 Hz signal is useful for decoding; the 935 Hz tones will be REVERSED.
    • The problem is mostly due to the IF and demodulator filtering. Many SSB receivers have a low passband edge of only 300 Hz, and some AM receivers have a highpass of 150 Hz. This applies during demodulation (like when making an audio recording or performing a live decode, or when demodulating an IQ recording to audio for decoding.)


  • Another method you can try with FLDigi;
    • Select the correct "Op Mode"
    • Use the waterfall's cursor and signal on a low frequency below the first tic mark.
    • Use the fine frequency arrow (found at the bottom center of the waterfall) to fine tune the frequency. The blue pen is indicating the rough frequency selection.
    • See this YouTube Video with an example (using QPSK63) of how this works.


My Images Decoding with MFSK Are Slanted

Calibration of the sound card

It is strongly recommended to calibrate the sound-card: click on the "Adjustments" menu button, then select the "Determination of the RX/TX sound-card sampling frequencies" option and push on the "Determination of the 48 KHz RX sampling frequency (test on 3 minutes)" button. At the end of the test, click on "Return",

Sound level

About the sound level ("Level" indication in % at the top of the screen): an AF level superior or equal to 10 % is OK. About 50 % is ideal (but not critical). In case of very low AF level, select "16 bits" in the "Determination of the RX/TX sound-card sampling frequencies" option ("Adjustments" menu button).


Are There Any Examples of These Applications In Actual Use?

These are YouTube videos with examples of each application above being used to decode an actual broadcast. There are many other examples on YouTube and a well formatted search will bring them up

Using DM780 (Ham Radio Deluxe)


Using FLDigi


Using MultiPSK


Does This Program Have A Social Media Site?


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