[Elecraft] K2: VFO clicks/pops in the presence of strong signals

[Linden, Mike (BRC-Hes)]

  I have just completed "Test and Alignment, Stage II" of K2 #4137.
Everything seems to have gone very well -- all Voltages were in range and it
seemed that everything worked as it should. However, I've now run across a
strange problem.

  I find that clicks/pops occur when I tune the VFO in the presence of
strong signals. For instance, if I set the XG1 for 50uV and tune the VFO up
and down from the XG1's frequency of 7040kHz, I hear clicks/pops (about
S-5/6) when the VFO transitions the following boundaries:

7015.79/80 (click/pop getting very weak here)
7020.79/80
7025.79/80
7030.79/80
7035.79/80
7040.79/80 (XG1's signal is theoretically centered at 7040.00)
7045.79/80
7050.79/80
7055.79/80 (clock/pop getting very weak here)

  The clicks/pops occur when I roll the VFO's last two digits
back-and-fourth across the .79/.80 boundary. The clicks/pops do not occur
when I turn off the XG1.

  I have also noticed that I can hear these clicks/pops when I get up around
7300 and strong broadcast stations are present.

  While I've seen a few mentions of this (or similar problems) in the
archives, I've never really seen any explanation or cure. Any ideas?

  Thanks, Michael N9BDF
          K2 #4137


PS  The "Amateur Radio Emergency Communications Consistency Act" (HR 1478)
and the "Amateur Radio Spectrum Protection Act" (HR 713 & S. 537) are in
Congress. Please contact your Congressmen to ask for their support of these
bills! See the following ARRL link for details:
http://www.arrl.org/govrelations/ <http://www.arrl.org/govrelations/>