[Milsurplus] Re: [Boatanchors] Removing beeswax from slug-tuned transform...

[WA5CAB at cs.com]

Groups,

I probably should have mentioned that the transformers I needed to remove the 
beeswax from were the double-slug tuned units in BC-611-F's.  The secondaries 
aren't easy to get at even if you remove the antenna and slotted guide tube.  
I've tried some of the suggested methods in the past.  But the result of any 
of the mechanical methods tended to result in learning that (a) the slug 
material is relatively soft and with any wax left in the threads the slotted tops 
of the slugs tend to break off and (b) the remaining slug material is 
relatively soft and not too much trouble to drill out, and the threads are #12-24 UNC 
(not a common thread today but taps are still available, fortunately).  I was 
hoping that my dim recollection that there was a magic elixer solvent once 
marketed by GC might have basis in fact.  But as no one mentioned it, I guess it 
was a dim dream.

I tried the hot soldering iron tip method but the molten stuff obstinantly 
refused to simply run out on a piece of paper towel I had placed on the 
workbench.  And given the access difficulty (tight quarters) and that some of the wax 
might get between the slugs where I couldn't melt it again (drill and 12-24 
tap time), I wasn't willing to attempt adjusting while molten.  So I reversed 
the air supply connection on my Pace desoldering station (and this time 
remembered to first clean the filter tube).  With a long curved straight-front tip, 
the Pace simply vaporised the wax and blew it out of the way (overhead fan 
blowing down on the workbench for a reverse fume-hood effect).  The trick was to 
first stick the hot tip down through the wax to the slug and then hit the pump 
foot switch briefly.  Presto, no more wax.

FWIW, I did check the IF center frequency before doing anything (if it ain't 
broke, don't fix it).  One pair was 6 KC and the other 8 KC high.  A little 
remembered consequency of IF misalignment in superhet receivers.  Which would 
have put the first receiver on 3991 KC and the second on 3993 KC.  

After re-tuning to 455 KC, I rolled a small amount of new wax into a rod and 
put it down the threaded hole on top of the slug.  The hot air from the Pace 
didn't work well for melting the new wax into the hole in a uniform manner.  
The hot air tended to melt the top of the wax and then blow it away.  But here, 
the hot (warm actually - turned controller down to 50%) tip of the soldering 
iron worked fine.  The new wax is off-white rather than dark brown like the 
original, but that's probably due to not having a 60 year accumulation of dust on 
the top surface.

I know Barry gave some disadvantages of beeswax for this application.  But 
the radios weren't mine.  I'll probably never see them again.  And at least, 60 
years from now, the next guy to do an alignment will find what the manual says 
should be there.  I'll bet that in 2065 you can still buy beeswax in hobby 
and craft stores.  But I wouldn't bet on any of the other suggested 
alternatives.  Probably no one would know what they are or how to deal with them.


73
Robert Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
<wa5cab at cs.com> (Primary email)
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