[Heathkit] Re: SB-303 fix up.

[Bob McGraw - K4TAX]

As I recall there is one of the brands and colors of spray paint carried by 
Lowe's that is very close to the original Heathkit color.  As to the wrinkle 
finish, can't say, but I understand that there is a way to make basically 
any spray type paint achieve that look.

I'll take a few minutes and browse the paint department next time I'm 
there,........ which will be Wed.  {I work at Lowe's but not in the paint 
dept}

As to cleaning cabinets, I've had good success with Windex and a soft artist 
brush for getting into the rough surface of the wrinkle finish.  Some of the 
other "heavy duty" household cleaners may cause damage to the finish or 
silkscreen lettering on front panels.  Proceed with care.  I've also used 
denatured alcohol {not rubbing alcohol} for some of my cleaning and 
restoration jobs.

73
Bob, K4TAX


----- Original Message ----- 
From: <kiyoinc at attglobal.net>
To: "Glen Zook" <gzook at yahoo.com>
Cc: <heathkit at mailman.qth.net>
Sent: Tuesday, October 09, 2007 6:27 AM
Subject: [Heathkit] Re: SB-303 fix up.


> Thanks Glen,
>
> What paint formula or mix do you recommend for SB cabinets?
> Now that I have the SB-303 home, I see that it's in fine shape but was 
> owned by a smoker at one time.  The cabinet smells and there is a grey 
> film on it.   I desmoked one before by washing the cabinet and wiping down 
> the insides with a damp cloth.
>
> This was someone's pride at one time and I will restore it to the best of 
> my ability.    It's dates to the 1970's, which makes it about 30 years 
> old.
>
> Couple odd things about this radio, there's a spinner knob attached to the 
> main tuning knob.  It's actually a nice job but I think I have a spare 
> Heath main tuning knob.   I got the manual with it.  The manual is well 
> worn, no surprise, but it is unmarked.  It looks like the builder chose to 
> build without putting check marks in his book.
>
> A fellow sent an off-list email.  Here are my answers to him.
>
> I like playing with Heathkits.  My first transmitter was a DX-60 in 1963. 
> I'm not an "expert".  I work on my SB-303's as I have time.  The radio was 
> $389 as a box of parts when a dollar was worth something.    I'm amazed 
> that people let these go for a couple hundred dollars.
> I have one SB-303 that came with 2 SSB filters.  The 2nd filter was simply 
> cascaded with the first.  There are no other components, just a couple 
> jumper wires.  It works very well.   Signals jump out as you tune across 
> the band.   If you tune across a strong carrier, the pitch changes and it 
> suddenly drops out.    12 poles of crystal filter sounds very good.
>
> In my experience, the electrolytics in the power supply should be 
> replaced.  I've seen some dripping white powder.
> Some SB-303's have corrosion on the capacitor shaft contact fingers in the 
> LMO.   This sounds like warbling or distortion when you tune across a 
> signal.   The voltage of the RF signal varies below spec and the waveform 
> jitters on a scope.  I had one that dropped out of oscillation.
> I also had an SB-101, tube LMO, that had a bad capacitor.  This was a 
> dog-bone capacitor, where the loop of wire at the end of the ceramic tube 
> was not soldered.   The symptom was a very unstable LMO.
>
> The LMO contacts are a bear to get to as you have to disassemble the front 
> of the radio to remove the LMO, unsolder it, open the LMO and then clean 
> the spring to shaft contacts.  Even with the LMO open, it's not easy. 
> I've used clean cardstock.  I also spray DeOxIt in there.
> I run the LMO on the bench with jumpers to the radio for power.
> Then to put the LMO back in, you have to realign the tuning mechanism as 
> part of the reassembly. This takes a hour or more.
>
> The crystal calibrator is dead half the time.  I haven't dug into this but 
> I'm guessing the problem is a resistor that's drifted out of spec.
> de ah6gi/4
> _______________________________________________
> List Administrator: Duane Fischer, W8DBF        ** For Assistance: 
> dfischer at usol.com **         $$ See the vintage area on the HCI web site - 
> http://www.w9wze.org $$ Heathkit mailing list
> Heathkit at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/heathkit