Sverre, LA3ZA wrote: "A simple question, do I have to realign the CW filter's BFO settings if I change the sidetone?" ========== Yes, you do, but it's very easy to do using Spectrogram. I have my K2's sidetone set to 400Hz, so I put a marker at 400Hz in Spectrogram to center the narrow filter passbands on while adjusting the BFO. 73, de Earl, K6SE