[Elecraft] KPA500 Issue

[Jim Clymer]

In my case, it was not the PIN diodes themselves, but failure of R9. I'm
away from my shack right now, so may not have the resistor ID correct. It
is a 48 Ohm resistor. I fixed the problem by parallel connecting a pair of
1/4 W, 100 Ohm resistors across the open one. Problem solved. Been fine
since.
There is documentation of this problem. A German ham wrote to me with a
link to the solution. If no one steps forward before tomorrow, I'll try to
post the info in the morning.
73,
Jim -  WS6X

On Thu, Mar 31, 2022, 6:40 PM Andy Durbin <a.durbin at msn.com> wrote:

> "However, what I’m seeing is that when the amp is in OPER mode, my receive
> signal strength drops way, way off to the point I have to go full AF volume
> to hear signals. If I put the amp in STBY, signal levels go back to normal."
>
> These exact symptoms have been associated in past reports with a failure
> of the TR switch PIN diodes.  Jack's idea of incorrect band can be easily
> confirmed, or eliminated, by looking at the KPA500 band display.
>
> Andy, k3wyc
>