[Elecraft] Amplifier T/R Keying problem

[William Stewart]

I have a problem trying to key a "homebrew" amplifier with my K2 (S/N 5251).
I am using the two-transistor T/R circuit from the "Mods" web page, and the
T/R relay pulls in as expected, however there is an annoying "thump" in the
received audio when the T/R returns to the receive state. I am using the
separate receive antenna (Rx) input. If I disconnect the receive antenna
line from the amp, there is no thump. If I trigger the T/R relay driver
circuit manually, there is no thump.  It seems that there is some
interaction between the receiver unmuting and the T/R relay going to the
"receive" state simultaneously that causes this thump. Any experience or
ideas?

 

Thanks,

 

Bill Stewart

WU0R