2018-08-13 Trying to receive amateur radio through local interference 2 years ago
This evening I tried several things to improve my chances of actually receiving anything other than the loudest stations in the upcoming SCC RTTY contest. First try was with a borrowed receive loop indoor and using an HF upconvertor, an rtl-sdr dongle and gqrx as receiving software. This did not work for digital modes: letting wsjt-x (FT8 software) 'listen' to the audio output of gqrx gave no decodes. Interesting detail: looking at the right piece of spectrum for FT8 showed that the frequency wasn't 100% stable, with frequencies slowly changing. Touching the rtl-sdr gave a bump in frequency. Another attempt was with the loop indoor and reception on the FT-857D radio. Reception of a strong SSB station seemed somewhat better on the loop, but I heard no improvement of weaker stations. So I moved the loop outside to the end of the garden and layed a long cable back to the radio setup. This made interference worse! It was already dark so this was not related to any solar panel setup, but some other source of interference on HF. The loop is supposed to receive less local interference but I could not get it to do that this time (it did work for SSB some other time).