[Elecraft] [K3] This might save you some grief

[WILLIS COOKE]

Wes, I had a similar experience.  I unseated the plug at the rear of the 
amplifier and reseated it.  Apparently one or more of the contacts had 
corrosion.  I just reseated the plug in the socket and normal operation 
returned.  I have read posts on this reflector of K3s that required the 
connector to be replaced because the pins on the connector had corroded off.  I 
think the newer units have gold plated pins to solve this problem.  My K3 is 
number 1025.
 Willis 'Cookie' Cooke 
K5EWJ 




________________________________
From: Wes Stewart <n7ws at yahoo.com>
To: Elecraft Reflector <elecraft at mailman.qth.net>
Sent: Sun, September 19, 2010 1:15:49 PM
Subject: [Elecraft] [K3] This might save you some grief

Yesterday afternoon 15-meters opened and I started to call a station only to 
find that I had very little transmitter power out.  Everything seemed to be set 
properly so I cycled the DC power and bingo I had proper output.  I chalked it 
up to cosmic rays (W8JI knows what I'm talking about) and went on the make the 
QSO. I tuned around a bit and found that 12-meters was open, found another 
station and started to call him and once again very little output.

I did briefly notice on the display an ERR message indicating a TX gain 
failure.  Going into Tune, I could only get about 40 W out while calling for 
100. This varied from band to band, with the lower bands actually being worse.  
So I decided to run the TX Gain calibration.  The first step on 160-meters 
failed at about 3.7 W.

Since I had the latest beta firmware installed, I decided to roll back a couple 
of versions.  No joy.  Time to take the lid off and look around.  I poked at all 
of the cables and the lead from the KANT3 board to the coax connector, which all 
seemed to be well-seated.

I contemplated removing the 100W PA, but logic said that it should be okay since 
it did make output more-or-less proportional to the apparent drive available.  
Time to run the TX Gain cal one more time before going further.  This time it 
failed at 2.4 W on 1.9 MHz.  Taking the lid off and poking around had made a 
difference.

I won't bore you with the rest of the two hours I spent investigating this and 
will cut to the chase.  Removing and replacing the KANT3 board fixed the 
problem.  Apparently, there was a problem with the interface connector between 
the KANT3 board and the main r-f board.

I had a similar problem with my old TR-7 years ago.  The digital display would 
get intermittent and required accessing the daughter board and moving it up and 
down on the interface pins to scrub off the oxidation.  This would last about 
three or four months until I had to do it again.

I hope this isn't going to be a recurring issue with the K3.








      
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