[Elecraft] K2 3 amps on receive

[Julian, G4ILO]

Lennart wrote:
> 
> When I powered on my K2 today it shut down after a few seconds. The 2 
> final transistors are warm but no power out. radio has been standing 
> without antenna or PS connected since last time I used it. Seems like 
> some bias level or driver is dead.  Last couple of times I have used the 
> radio has been during tests of my new RS232 interface that worked very 
> well, but that is removed now during fault finding.
> 
> Any tip on where to start looking? Serial no 6403.
> 
> 
I vaguely remember (it was a long time ago) that I had a similar problem
when building my K2. There is a component, an inductor I think, that
provides negative feedback to the driver stage. It was O/C so the PA went
into oscillation when the rig was powered up, and blew the driver
transistor.

Why yours should suddenly go O/C after being OK I don't know, so it could
well be something else. It could be failure of the device that switches the
supply to the TX stages, so the TX side is getting power during RX when it
shouldn't be.

-----
Julian, G4ILO. K2 #392  K3 #222.
http://www.g4ilo.com/ G4ILO's Shack   http://www.ham-directory.com/ Ham
Directory    http://www.g4ilo.com/kcomm.html KComm for Elecraft K2 and K3 
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