[Elecraft] K3/10 low power output, fails TX calibration?

[Russell Tobolic]

Hi Ross;

This looks exactly like the problem that I just recently experienced on #732.  It turns out that one of the output FETS (Q5) in my LPA developed a gate to source short. Check the gate to ground resistance on each device which should be 1K-4K ohms.  You should contact gary @ elecraft on instructions for a recent modification of the LPA to help with this issue.

I replaced Q5 and everything is almost back to normal but now I am working through another issue at this time.

Russ,
N3CO



________________________________
From: Ross Primrose N4RP <n4rp at aiko.com>
To: Elecraft Reflector <elecraft at mailman.qth.net>
Sent: Sunday, March 13, 2011 9:33 AM
Subject: [Elecraft] K3/10 low power output, fails TX calibration?

My K3 #5143 has suddenly developed a low power output problem. Even with 
tune power set to 7W, it can only generate 3.5W or so on all bands 
except 40 & 80, where it can still produce 7W. Running the TX 
calibration in the K3 utility generates a failure when it starts as it 
can only do 3.7W on 160.

Ideas?

-- 
FCC Section 97.313(a) “At all times, an amateur station must use the minimum transmitter power necessary to carry out the desired communications.”

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