[MRCA] PE-104-A Conversion to solid state successful- SCR-284 - corrected link

[Robert Downs]

FWIW,  WW-II and Korean War vintage military and civilian radio vibrators usually do not work (especially if NOSB) because the contacts have formed a non-conducting  layer of Tungsten Sulfate or Sulfide (I never tried to determine which) due to Sulfur out-gassing over the decades.  It is usually possible (about 98% success rate) to clear the contacts without opening the can.  The method uses a minimum of two 120 or 220 VAC incandescent lamps properly connected.  Three lamps will save time.  Once cleared, the vibrator should have a normal service life so long as it is operated at least every few weeks.  This method can be applied to all radio vibrators except for the VB-5, which has an internal low value resistor across the coil contacts.  And you wouldn’t need to use it on the VB-16 as its cover is removable.  

 

Robert Downs

 

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