After considerable fiddling with settings, listening with different signal conditions, etc. I still have more clicks/thumping with 017, board 3 on the high band QMX than I experienced with the low-band using 014 software. I noticed that the click on key down was not the same as on key up, and this difference can be heard easily when keyer speed is zeroed. Make sounds like a click, isn't really too bad, but break sounds like? 'poink' to me. May be what others are calling 'thump'.
I tried capturing the audio signal with scope triggered on key closure and I notice that there is a distinct short burst of audio following the trailing edge of a keying mark--see attached photos QMXaudio4.jpeg and QMXaudio5.jpeg. The difference between these two is that the first used the paddle input directly, the second is from my bug sending a dot connected via an external debouncing circuit. The settings photos are as for the audio pictures, except that the audio was captured with the keyer in practice mode--the result is similar when the Tx is on, but there is enough rf pickup from scope leads etc. to make the trailing blip less clear. The audio was sampled across a 2.2K resistor for the photos to check that the headphones were not involved. With headphones, the audio is similar, but lower in amplitude.
...Joe VE7BFK
