[Elecraft] K1 went out!

[Don Wilhelm]

  Stan,

Since the K1 was operating into a high SWR, the most likely failure is 
the zener diode across the PA transistor output - it is there to kill 
high RF voltage spikes, and with a high SWR, the RF voltage will be 
either lower than normal or higher than normal at the PA collector 
depending on whether the feedline impedance is high or low (Ohm's law 
prevails).

The diode is D19.  Try removing one end of it and see if the K1 
transmits into a dummy load - if it does, then just replace the diode.  
If it still does not transmit, it is likely that the PA transistor 
and/or one of the components in the PA output have also been damaged.

Moral, do not operate the K1 (or most any other transmitter) into a high 
SWR.

73,
Don W3FPR


On 1/4/2011 1:46 PM, Stan Grigaliunas wrote:
> I purchased a used K1 without the ATU.  I had it on receive 40m for couple hours.  All worked great being hooked up to a G5RV.  I went through the Menu, checked all the parameters, and only changed one option. ( set Filter 1 from 300 to 200 ).  Then I got brave and plugged in a key!  The radio was powered by Radio Shack 3 amp supply.  After sending about a couple dozen of VVV’es, the K1 shut down and will not come to life.  The power supply is ok, 13.8 volts, but when I turn the power ON, the voltage goes way way down to almost nothing.  Nothing seems to run hot or even smoke.  The 3 amp fuse in the supply does not blow.
>
> This is my first experience with K1. I took the top cover off and looked around. Looks like it was built by a professional.  Soldering is perfect, like it was done by a machine.  Very impressed on the workmanship and construction.
>
> Any good suggestions what to look for?  any recommendations on a decent repair shop?
>
> 73
> Stan
> K8SRB
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