[Elecraft] K2 PA KEY (J7) stopped working

[W3FPR]

Chris,

Yes, the most likely suspect is Q9, but it is quite hardy and seldom fails.
Take a look at the gate voltage to Q9 while keydown (you can set the 
power to zero for that test, or work the K2 into a dummy load).
If the gate voltage goes to 5 volts or so, then Q9 is the problem.  If 
it stays near zero volts, then one of the drivers to Q9 gate has failed.

73,
Don W3FPR

On 7/13/2024 1:54 PM, Chris wrote:
> Hello,
>
> My K2/100 has an issue with the PA KEY (J7). With the key down, it has
> about 350k ohms as opposed to the specified 3 ohms. Will replacing Q9 fix
> the issue, or can there be other areas that can cause this issue?
>
> Many thanks,
>
> Chris KM1B
>