For almost nine months now I have had an itch to get into amateur radio in some way or another. It started when I had been reading about shortwave radio and I wanted to listen to it for myself, so I tried to find a circuit diagram of a simple shortwave receiver that I could build on my breadboard. And it didn’t work. Then a little while later, for some reason or another, I tried to build an SDR (software-defined radio) quadrature mixer to let me experiment with a range of radio encoding methods on one of my Linux computers. And it didn’t work. Then I decided to keep it simple and just build a direct-conversion CW (Morse code) receiver – not much to go wrong there. And it didn’t work.
See the pattern here? Yes, none of them worked. And today, even after I managed to receive and (manually) decode the 60kHz MSF time signal with the help of (the same) Linux SDR program, I still failed to get a simple frequency mixer working in order to tune higher up the LF band. And I only managed to get the time signal experiment working because the sound card in my new computer can sample at up to 192kHz sampling rate, and 60kHz is thus below the maximum tunable frequency of 96kHz, meaning that I practically just had to connect a fairly long random-wire antenna to the line in port on my computer, fire up the SDR, and type in “60kHz” – not much of an achievement there. Heck, even the magnetic loop antenna didn’t work.Read More »