I had my first real taste of radio decoding back in the 90’s. Things were a little different then though. For starters you needed a scanner or HF radio (or both), a demodulator (from Pervisell), leads to connect the radio audio output to a computer soundcard and of course software (or just plain old DOS) and a PC to process everything. At the time I had a subscription to Shortwave Magazine (sadly no longer in print) and the decode section was a godsend.
Each decoding practice had different protocols and often things didn’t work out as planned. Many hours (or days) were spent tinkering with leads, interface settings (bloody COM ports!) and antenna locations. If you were unlucky the Windows blue screen of death would make an appearance every now and again!