[Elecraft] Weird Problem with rcvr sensitivity

[KJ3D]

Good Evening Group,

I believe I have seen this problem, but I cannot remember the solution.

K2/100 (4991, all mods).  Above 70 w, and after a short string of dits and
dahs - maybe like a CQ, the receiver comes back about 15 dB down from where
it was.  Very noticeable.  After a random string of dits and dahs, it comes
back up.  

I've tried this with all manner of settings of AGC, DSP, noise filters etc.
etc.  Can't find anything that contributes to the problem except power.  The
antenna is resonate, but I do have KAT100 in the line.  Everything works
perfectly below 70 (or so) watts.

Anybody remember the solution?

Thanks, es 73

Tom, KJ3D