[Hallicrafters] Price range of SX 28

[Mike Everette]

Take a look at these web sites:

www.antiqueradio.org (or is it .com)

This is as close to a "Heathkit" restoration guide as
you will find.  This deals with the SX-28, not the
28A.

Also do a Google search for "SX-28, a Pre-war
Masterpiece."  This is a great article from the
Western Radio History Museum in Virginia City, NV. 
Much, much info about differences in SX-28 models and
production runs.

Restoring an SX-28 is not an easy project (I am still
working on mine, as time allows), but I suspect there
are much more difficult ones out there.  In some ways
I wonder if Hallicrafters intended for several models
to be worked on -- the 28 and (especially) 42 come to
mind.  But it can be done.  Others have been there
before you and marked the trail.

I personally would prefer an SX-28 to a 28A.  

The 28A was supposed to be designed for ease of
maintenance, but that is very debatable.  Each version
has its own set of pitfalls.

The only real way to tell the difference between a 28
and 28A is by looking under the chassis at the RF
deck, and in particular the coils.  There is a
distinct difference.  There are web sites that will
show you.  Not many 28As had front panels actually
stamped "SX-28A."

The rack-mount versions, with dust covers rather than
cabinets, often are in a little better shape in that
they are cleaner and don't seem to have quite the
problems of rust on top of the chassis that the
cabinet-units sometimes exhibit.  It seems to be rare
to find a rack-mount unit with its original chassis
bottom cover, but they did originally have one, and it
covered the entire chassis.

The units with gear-driven bandspread tuning, rather
than a dial cord, are (to me at least) better.  Most
of not all SX-28As had cord-driven bandspread.  This
was a cheapifying measure by Hallicrafters.  It's a
potential source of later trouble.

When taking off the front panel, one pitfall that no
one seems to have documented is the need to have
already loosened the flexible fibre shaft couplers,
especially the one on the crystal phasing control.  If
you don't loosen it first, it WILL break! (been there,
done that, but Super Glue may fix it)

Be careful of the dials.  They are brittle and easily
broken.

When you get to the point of aligning the IF, be sure
and read Bill Feldman's procedure which is accessible
from the W9WZE web site (I think) or the
antiqueradio.org site.  It is far better than the
manual.

Speaking of manuals, no matter which version you have,
go to BAMA and download the one for your model.  Also
be sure and get the manual for the AN/GRR-2, the mil
version of the SX-28A, even if you have an SX-28,
because there is much more info in this book than you
will find anywhere else -- including the dial cord
restringing diagrams.

As for price?  Hard to say.  If it works even a
little, it's obviously worth more -- but you will have
to recap it anyway, and probably also replace more
than half the resistors! If it's clean, and works,
it's worth more.  If it doesn't work but is clean (and
the transformer is good, obviously) it's worth less
than one that does work, but how much is hard to say. 
If it's dirty and not rusty inside, and the
transformer's good, it may be a good bet for
restoration.  If it's rusty inside, be careful.

Use your nose.  If you smell a burned transformer, be
very very careful, no matter how clean it may be.  

No matter how clean, etc., you will have to restore it
(read: rebuild it) unless it's already been restored. 
Don't ever consider an SX-28 as plug-n-play.

Even if it seems to work, replace the input coupling
caps in the audio output stage immediately.  If these
caps are leaky and cause the output tubes to draw too
much current, the audio output transformer will likely
get fried, and they are not easy to find.

This radio is a tough one to work on, but take your
time!  The results will be worth it.  And keep good
notes as you replace parts!!  Draw pictures if you
take more than one thing loose at a time.  It will
save you much grief later.

73

Mike
WA4DLF



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