Emulating a full FT8 band for 'real'

This code generates a .wav file which emulates a fully-populated FT8 band!

This .wav file can then be played with rpitx on actual air (well on a dummy load) for receiver testing purposes.

rm mixed.wav; sox -m *.wav mixed.wav

sox mixed.wav -r 48000 sampleaudio.wav

Now play sampleaudio.wav using https://github.com/F5OEO/rpitx.

I have tested https://github.com/F5OEO/rpitx on Raspberry Pi Zero 2W TX'ing @ 14.074 MHz.

References:

• https://github.com/kholia/ConsensusBasedTimeSync/tree/master/Wide-FT8-Tester

• https://github.com/kgoba/ft8_lib/ (source for gen_ft8 binary)