[Boatanchors] KWM2-A NO DRIVE SOLVED

Al Parker anchor at ec.rr.com
Tue Jan 6 13:08:05 EST 2015


Hi Bill,
	Thanks for the update, it's always nice to hear what solved the problem.
73,

Al, W8UT
www.boatanchors.org
www.hammarlund.info

"There is nothing -- absolutely nothing -- half so much
worth doing as simply messing about in boats"
Ratty, to Mole

On 1/6/2015 12:58 PM, Bill and Liz wrote:
> Thanks to all who gave me helpful suggestions.  After measuring the level at the grid of the driver tube I realized that, while there was drive, it was way too little to overcome the bias on the tube in TX mode.  So I worked my way back until I came to the first TX mixer and there on the socket of the 12AT7 was a cold solder joint!  The radio now performs as it should, better actually since I peaked up all the stages in the transmit chain while I was troubleshooting.
>
> The Collins manual does not provide stage gain measurements so I was in the dark as to how much drive was required.  I have now recorded the readings for each stage should this little beast act up again.
>
> Bill VE3NH


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