[Hammarlund] AVC Mod For HQ129X

[Edward Gable]

If ur 129-X is distorting on strong AM signals with AVC ON and RF gain
control full, you don't need a modification, you need to repair the AVC
system.  The HQ-129-X should not overload under those conditions. (AM, AVC
on)  Most AVC problems in older receivers are bad tubes, leaky AVC by-pass
capacitors or changing high value resistors.  Since the AVC system is so
high impedance, several meg-ohms of AVC voltage source resistance, even
small leakage in by-pass capacitors can load down the AVC voltage.  High
impedance leakage and/or gas in tubes can do the same and often are
undetectable in tube testers.  Good luck with your 129, a nice classic radio
indeed.  73,  Ed k2mp, Curator, AWA Museum  (www.antiquewireless.org)

----- Original Message ----- 
From: <Rivpapa1 at aol.com>
To: <hammarlund at mailman.qth.net>
Sent: Wednesday, April 06, 2005 8:13 AM
Subject: [Hammarlund] AVC Mod For HQ129X


> Anyone have the avc mod for HQ129X that will stop distortion on strong
> signals?..Tnx Ron W6MAU
> _______________________________________________
> List Administrator: Duane Fischer W8DBF
> ** For Assistance: dfischer at usol.com **
> ----
> http://mailman.qth.net/mailman/listinfo/hammarlund