[Hammarlund] HQ-180 service bulletins and recommended mods

[Glen Zook]

Go ahead and recap including the electrolytics!  Older electrolytics are a time bomb and when they go, they usually "take out" other components and, following Murphy's Law, those components are going to be hard to find as well as expensive.


New electrolytics are cheap and replacing them is definitely insurance against having to pay a lot more to "fix" the radio in the future.


 
Glen, K9STH 
Website: http://k9sth.net

      From: Jeff <jeff at podengo.com>
 To: Hammarlund <hammarlund at mailman.qth.net> 
 Sent: Monday, May 23, 2016 9:19 PM
 Subject: [Hammarlund] HQ-180 service bulletins and recommended mods
   
Hi All -

Just found a good HQ-180, and have it on the bench for its initial 
walk-through.  The BAMA site has the manual for this particular one in 
the "issue3" sub directory -- it looks somewhat different than the other 
180s I've seen.  I would say it's probably an older one, but I don't 
know for sure.  The serial number is 631.

Previous owner put a toggle switch on the back that seems to control the 
AC line. I haven't figured out why yet -- as it took me a minute or two 
to figure out how to turn it on (it has a clock...  my other ones don't).

I plan on pairing it with the HX-500.  Here's the question to you 
Hammarlund experts: any mods that ought to be done?  I've read that 
people "convert them to the HQ-180A," but this seems more involved than 
just putting some diodes in and upping the B+ dropping resistor from 2K 
to 3K.

This one is pretty badly out of alignment, but the filter caps seem 
good. After replacing a few tubes, it hears signals, but audio is poor 
-- no recapping yet.  It also doesn't appear to have the secondary 
filament transformer that lights the oscillator and mixer full time, so 
I expect a bit of drift.  Can anyone offer any insight on this 
particular edition of the 180?