[Hammarlund] HQ-170 Mods

[Singley, Rodger]

Bill,

You can add a separate filament transformer to keep the HFO and mixer powered on at all times; I believe this was done in the A models of the 170 and 180.  Hallicrafters used an always on filament transformer for the oscillator and a power resistor across the line (physically mounted to the chassis to keep it warm) in the SX-101 series to reduce drift.

The HQ series Hammarlunds with a 6C4 HFO are pretty picky about the particular tube used and it pays to have a variety of 6C4's to select from with these receivers.

I mostly use my 170, 170A, and 180 on 40 and lower so drift has never bothered me but perhaps it is an issue on the higher bands.

Rodger WQ9E


-----Original Message-----
From: hammarlund-bounces at mailman.qth.net on behalf of bill bryant
Sent: Thu 10/8/2009 12:37 AM
To: hammarlund at mailman.qth.net
Subject: [Hammarlund] HQ-170 Mods
 
Does any one know of any mods that will stop the HQ-170 from drifting? Thanks, Bill



      
______________________________________________________________
Hammarlund mailing list
Home: http://mailman.qth.net/mailman/listinfo/hammarlund
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Hammarlund at mailman.qth.net

List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer at usol.com ** 


This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html