[Collins] KWM-2a RE meter not dropping to zero when powered up

[Dr.Gerald N. Johnson]

Dr. Gerald N. Johnson, Electrical Engineer
----- Original Message -----
From: Cam and Juli Hedrick [mailto:walnutcreek at appstate.net]
Sent: 8/31/2005 8:33:47 AM
To: collins at mailman.qth.net
Subject: [Collins] KWM-2a RE meter not dropping to zero when powered up

> Hi all, 
> I'm thinking the AGC circuit as well, it has recent caps and this just
> started.  I tried replaced V7 and got the same results.  I'll dig deeper
> next chance to see if maybe a value has changed in one of the caps.
> Otherwise, does anyone have any ideas?
> Thanks and 73,
> Cam
> WA4JKW
> 
> 
> 
A changed value in one of the large paper capacitors should only change the AGC time constant, not the standing value. More likely a resistor has changed value, possibly partly the effect of soldering heat when replacing the capacitors. The S-meter zero pot is suspect as are resistors in that circuit. The meter switches through the relay and so does receiver DC voltages, which makes the relay contacts continue to be suspects. Try zeroing the meter with the s-meter zero pot and see if it stays.

73, Jerry, K0CQ, Technical Advisor to the CRA
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