Joachim's Ham-Radio and Radio-Frequency Blog (A Solderful of Secrets) - from Longwave to Microwaves
Wednesday, October 28, 2009
30m QRSS-RX modification
Recently, I have seen some traces of lower sideband interference in my 30m-qrss receiver. Thus, the filter crystal went back in again. This time, with some experimentation and thinking. The crystal is now in series with a 22pF capacitor, pulling it just a little, such that the resonance is about the qrss band and a little bit above. Doing so, I hope to have removed contributions of the lower sideband.