[TowerTalk] Roller Inductors

[zl1aih at ihug.co.nz]

> I recently returned to the air after an eight year absence.  The 
> roller inductors in my Nye MB-V-A and my Ten Tec 4229 antenna tuners 
> have corroded and are intermittent.  I have squirted contact cleaner 
> on the coils and rollers and run the rollers back and forth with no 
> improvement.  Does anyone have any suggestions?
> 73, Hank, W6SX
> Mammoth Lakes, California 



The RCA manual for their AT3 transmitter (WW2) recommended a mixture of 
anhydrous lanolin and carbon tetrachloride as a lubricant for the roller carriages.
I still have some anhydrous lanolin but carbon tet is no longer available in NZ.

My local chemist ('drugstore' in US) sold me a small bottle of trichloroethylene after 
strict examination and sure information from the RCA manual revealed that my 
intentions were entirely legal.
   
This mixture works very well - one of these big roller inductors (edge-wound) is in 
daily use in a "C-L-C" antenna tuner and has not needed any maintenance during 
three years of serious CW contesting - not bad for 1942 manufacture.   

I salvaged several roller inductors and big Hammond variable capacitors from the 
AT3 - all were covered in dust, gunge and mould.   While the XYL was away visiting 
her mother, I put them all through the dishwasher - ceramic end-plates came out 
pristine white and the metal looked brand-new.

73, Ken ZL1AIH (one of the ZM1A Team)