[Hallicrafters] Caps on Selectivity switch was: RE: SX-100 Knobs

[David C. Hallam]

I will add one detail to my work on the SX-100.  I recently bought a 
Hakko 808 desoldering gun.  As far as I am concerned, they are amazing 
in their ability to clean solder off of connections.  They made my work 
of replacing capacitors and resistors much easier.  I could get into 
tight places and suck a joint clean.  I never had good results with 
solder wick, make that any satisfactory results, and solder suckers 
worked but never to the point I was happy. Mostly I relied on clipping 
the part out, sucking out what I could with the iron and a solder 
sucker, and then using my  iron to melt what solder was left, and 
wiggling the wire as the the solder cooled.

David
KW4DH

On 7/8/2013 6:05 PM, David C. Hallam wrote:
> I had expected it to be a real horror story, but turned out to be not 
> too bad.  Although that may be an understatement.  What I did was to 
> take the switch loose from the front panel.  There was enough slack in 
> the wires to allow me to pull the switch shaft through the chassis and 
> rotate the rear of the switch up about 30-45 degrees.  I then replaced 
> the capacitors and resistors on the back wafer.  Then I loosen the 
> nuts on the two screws that hold the wafers on the switch.  By 
> removing the rear wafer I was able to move it out of the way to get to 
> the resistors and capacitors on the center wafer.  I didn't do 
> anything with the resistor on the front wafer.
>
> I used CDE 5% axial film capacitors from Mouser.  I also ordered some 
> Panasonic 0.0047 and 0.01 3% radial polypropylene but they didn't have 
> any in 0.022 uF.  I thought I might be able to find some 0.022 3% but 
> didn't by the time my Mouser order arrived.
>
> The rest of the film capacitors used were standard 10% axial.  All the 
> replacement resistors were 1% metal film.
>
> Hope that helps.
>
> 73 David
> KW4DH
>
> On 7/8/2013 5:41 PM, Chris Kepus wrote:
>> Sounds like a first class project, David.
>>
>>
>> Don't know about the knobs but I am curious about your re-cap effort.
>> (others who have been "there - done that" feel free to chime in)
>>
>> What did you do to replace the caps on the selectivity switch? I am 
>> in the
>> re-cap process working my way in that direction.  All I have to do to 
>> feel
>> nauseous is look at that darn switch.  I think I'd rather chew on 
>> aluminum
>> foil than attack that mess. ;-)  Anyway, please tell me how you 
>> accomplished
>> the job and then tell me exactly how much fun it was (and that it 
>> isn't as
>> bad a job as it looks.)
>> Thanks es 73,
>> Chris
>> W7JPG
>>
>> -----Original Message-----
>> From: hallicrafters-bounces at mailman.qth.net
>> [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of David C. 
>> Hallam
>> ent: Monday, July 08, 2013 10:39 AM
>> To: hallicrafters at mailman.qth.net
>> Subject: [Hallicrafters] SX-100 Knobs
>>
>> Did Hallicrafters use anything protective varnish or similar on the knob
>> skirts?  Mine were all yellowed and I assumed it was cigarette smoke
>> residue.  After a trip through the ultrasonic cleaner, whatever was 
>> peeling
>> off the skirt.  Nor just dissolving but peeling off in little pieces.
>>
>> I just finished the replacing of electrolytic and film capacitors. I 
>> used
>> 10% polypropylene except for the pass band where I used 5%. I also 
>> replaced
>> any resistors more than 7% out of spec using 1% metal film.
>>
>> It is working but is a little deaf.  I was listening to 40M with a 2 ft
>> piece of wire.  Now to start the alignment.  It is SX-100 MK2.
>>
>> David
>> KW4DH
>>
>> PS: All the film capacitors were the red Tiny Chiefs.  I tested all 
>> of them
>> with my Sprague capacitor tester after removal.  I did only a quick 
>> test to
>> see if a capacitor had rated capacitance.  Only one was bad but I 
>> knew it
>> was bad before removal.  The resistor associated with it was burned.
>>
>> Since these capacitors were 60 years old, I decided it was time for 
>> them to
>> be retired.
>> -- 
>>
>>
>

-- 
"I predict future happiness for Americans if they can prevent the government from wasting the labors of the people under the pretense of taking care of them."
Thomas Jefferson