[Hammarlund] HQ-180 service bulletins and recommended mods

[Jeff]

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?

Thanks!

Jeff
WB3JIH