[Hallicrafters] Novice Seeking Recapping Advice

[Rob Copeland]

Hi Guys,

Please don't take it the wrong way, but I found replacing everything was a
lot faster for me.
I started out testing this and testing that but it is that testing that got
me bogged down.
Once decided to just replace everything and realign/test later when I was
done things went about twice as fast.
Granted it could be possibly more money perhaps maybe even double what you
would spend. However, you won't
have to go back and replace more parts later. My focus was to enjoy
listening to the radio not spend more time
working on it. Most everything in these old radios is prone to go a lot
faster than components that are used in
newer stuff these days.

As for the initial power up and alignment I totally agree use a variac and
power up
slowly as moisture in a transformer that has been sitting could possibly fry
it if the power is suddenly
slammed full on. A ham buddy of mine actually pulls the transformer and slow
cooks it in the oven or puts
it on his woodstove. This will get rid of any stray moisture that could
short out the windings in a transformer.
I have heard and seen many a transformer that measured a shorted coil be
brought back to life this way. Of course
Do a resistance check first if you must but it wouldn't hurt to do a low
temp bake.

Make sure you have all of the proper alignment equipment. The better you can
get it aligned the
better the operation of the unit.

In the end the most important enjoy it. These Old Halli radios are works of
art in my opinion. And it
is very obvious to me how much people appreciate them here. Heck I am not
even a ham operator.
I just enjoy listening and admiring the look of the radio. These old
Hallicrafters have a look about
them. That was what caught my attention to my sx-28 in fact that is what got
me the radio. My ham
friend just gave it to me.

I feel VERY Lucky!

Rob :)

-----Original Message-----
From: hallicrafters-bounces at mailman.qth.net
[mailto:hallicrafters-bounces at mailman.qth.net]On Behalf Of Edward B
Richards
Sent: Friday, July 27, 2007 12:09 PM
To: lucek at akaRX.com
Cc: hallicrafters at mailman.qth.net
Subject: Re: [Hallicrafters] Novice Seeking Recapping Advice


Hi Rudy;

I think most of us do it the same way. Pull all the tubes and anything
else that unplugs. Test and clean the tubes. Clean the chassis and
cabinet and knobs and tighten all the hardware and then reinstall the
tubes, etc. As for recapping... there are two school of thought there.
Some people replace every cap. That can be a chore as some of them are
nearly inaccessible behind other parts, inside IF cans, etc. The other
school (which I belong to) only replace certain ones, All coupling caps
should be replaced as just a small amount of leakage can forward bias the
following stage and overload it. Black beauty and other caps with high
leakage/failure rates should be replaced as well as any that look bad
(dripping wax, discolored, etc. I measure all resistors in circuit, which
won't give you an accurate picture, but by looking at the circuit can
give you a clue. Plate and screen dropping resistors that have no load on
them other than the tube should read right on. I open one end of any
questionable resistors and measure them open-circuit. Replace any that
are out of tolerance. No 4th band is 20% tolerance, a silver 4th band is
10%, a gold 4th band is 5%.   People in a hurry clip the leads and solder
the new part to the stumps, Others that want a neat, original look
unsolder the old part and remove all of the lead. Be careful not to apply
too much pressure and break something. Next you apply voltage through a
light bulb (to limit the current if something shorts). Measure the B+
while you do this. There should be a slow but steady increase in voltage.
When you are satisfied all is ok, remove the bulb and measure all the
voltages per the manual. When all is OK, realign and recalibrate it.
Remember that the line voltage is higher now than when the set was made.
If you value the power transformer, use some kind of voltage reducer. See
BAMA home page for a circuit for a simple voltage reducer, by K6UUZ.

73,   Ed   K6UUZ

On Fri, 27 Jul 2007 14:22:38 -0400 "Lucek,Rudolph" <lucek at akaRX.com>
writes:
>
>
> I am planning to begin my first restoration project on an SX110 that
> I
> purchased on Ebay.  I have not done a restoration before and would
> appreciate any advice anyone could offer.  The unit is in very good
> shape and after doing a general cleaning I plan to recap it.  To
> replace
> the capacitors should I unsolder them completely or can I cut the
> original leads leaving the leads soldered in place and splice in the
> new
> capacitors?  It seems that splicing would be easier but is it the
> best
> way to do the job?  Should I replace all the resistors or should I
> replace only those that test out of tolerance?  Any guidance anyone
> can
> offer in tackling my first project would be appreciated.  Thanks,
> Rudy
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