K1 Filter Realignment

I have played some more with the filter board. I decided not to worry too much about it because the trimmers will be altered again during transmitter alignment, but here are the alignment results so far:

  • 20/17: Good strong signal. No difference if I put my fingers close to the filter board. It is no problem to hear the 1uV signal from the XG-2 on 20 even with attenuator ON.
  • 30: Relatively good, ie. better than before. I can approach the filter board with my fingers without making any difference.
  • 40: Very similar to 30. The 1uV signal from the XG-2 is not strong but hearable even with the attenuator ON.

I am quite satisfied with this result. The sensitivity on 40 meters may not be as good as on 20 and 17, but I will not need very high sensitivity on that band either. Normally, people use attenuators on 40 meters anyway and besides, I can hear the 1uV signal without problems.

I have also played with the RIT and XIT functions and they work fine, at least the RIT. The BFO has been adjusted as well to approximately 700 Hz but I will redo that alignment using an audio spectrogram program.


Author: Alexandru Csete

Embedded software engineer in the satcom industry during the day. Radio amateur and SDR hacker during the night.