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Weak Signal Communications Software Everywhere on HF

weak signal communications software

Sometimes, all you can see on the ham bands are weak signal communications software exchanges chugging away. Are these robots or real people? 

Anyone who listens to the ham bands these days should know that weak signal communications software has taken over. Your most popular choice is WSJT-X which implements most of the important modes. These include FT8, JT9 and WSPR. Using these digital modes, hams can achieve amazing contacts with low power and quite a bit of noise immunity.

In fact, some days FT8 and FT4 are the dominant (and sometimes only) signals you will see on some bands. The graphic above shows FT8 signals starting at 14.074 MHz and FT4 exchanges starting at 14.080 MHz. Both of these modes are just a bunch of tones shifting in frequency during an exchange window. The transmission windows are 15 seconds for FT8 and 7.5 seconds for FT4.

Setting up FT8 communications is really easy after you install the WSJT-X software. First, connect the audio from your receiver. In addition, you will benefit from connecting the software to your logging program and transceiver control. Nothing new hear for most hams and radio listeners.

Second, check your audio levels and reduce your transmit power. Most people use 5-20 watts for these modes, because that’s all you need. Finally, synchronize your PC clock to a time standard and keep it synchronized. You will find it’s easy to set this up in Windows and just forget about it.

If you are a SWL, all you need is the audio from your receiver. Tune to the right frequencies and WSJT-X will decode everything for you to follow along. When I first wrote about FT8 two years ago, it was something new. Now it dominates much of ham activity.

Weak Signal Communications Software Robots

In general, FT8 communications still require a human operator, even though the QSO sequence is largely automated.

However, some enterprising hams have fully automated exchanges with FT8 and FT4. For example, SV5DKL in Greece uses keyboard macros to automate exchanges with WSJT-X. If you follow his instructions, you can turn your PC into a robot to do your ham radio for you.

Needless to say, these approaches have caused a lot of concern in the ham community by removing the operator from the process. But I suspect they are being increasingly used. After all, you can work DXCC in a few weeks rather than years, albeit through questionable unattended operation.

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