[Hammarlund] HQ-180 Power Transformer

[RJ Mattson]

Mark
I would leave it alone. Here are a few ideas:
Your 180 might have been an escaped  lab prototype.
Maybe the original xfmr smoked and the owner bought an updated xfmr.

The 180a was an improvement. Less current and  drift.
I don't think the xfmrs will effect value if presented as a positive repair.
Slip a 180a schematic in the 180 manual. Make a few notes/readings on your 
observations
Enjoy your 180Special. It's a great rcvr.
bob...w2ami


----- Original Message ----- 
From: "Gilbert Guimaraes" <gmark.guimaraes at verizon.net>
To: "Tim Kass" <timkass at hotmail.com>; <hammarlund at mailman.qth.net>
Sent: Friday, March 31, 2006 10:15 PM
Subject: Re: [Hammarlund] HQ-180 Power Transformer


Thanks for all the great info and suggestions.  This is my first boat
anchor, but I do have experience maintaining and repairing electronics,
but not a lot of experience with tubes. That said, here is what info I
have gathered from reading the Op/Service manuals and various web sites.

I have a basic HQ-180 with the optional 24-hour clock-timer installed.
That according to some web sites makes this an HQ-180C.
The basic 180 has a tube rectifier and the power transformer is a single
PRI with three SEC windings: 260-0260 Plate voltage, 6.3 VAC filament
and 5 VAC filament for the rectifier tube.

The 180A has no rectifier tube, it uses dual solid state diode.  The
power transformer has a dual PRI, connected in parallel and a dual
secondary: ?? Plate voltage and 6.3 VAC filament.  It has an additional
transformer, T22 that provides filament voltage for the HF osc and mixer
tubes any time the set is plugged in, this keeps the tubes warm and
reduces drift at start up.

My 180 has a solid state rectifier, dual PRI/dual SEC main transformer
and another transformer hooked to filaments of the HF osc and mixer,
this includes a toggle switch on the back that turns power to second
transformer.  The Volt Regulator is not the one specified.
Some of this looks home brewed by someone who had excellent technical
knowledge, and some good craftsmanship skills.
The set does work but here are my questions.

1. Should I leave the set  as is, since it works, but without any notes
about these parts and should fail have troubleshoot or replace them blindly?
2.  Could Hammarlund have made an almost 180A, modified the power supply
section, but not the rest or offered a kit to upgrade from the basic 180?
3.  Would restoring the set to its original configuration be important
value wise?
4.  Where is the serial number located?

Thanks
Mark