[Milsurplus] Vibrators

[WA5CAB at cs.com]

George,

My empirical experience indicates something on the order of half a century of 
no use before the contacts don't (make contact).  Ten years ago and back, the 
Korean War vintage ones virtually always worked out of the box and most makes 
of WW-II ones didn't.  Recently (last couple of years at least), Korean War 
ones usually do not work out of the box.   And for both groups, vibrators 
installed in equipment that had been used (i.e., not also NOS) were/are more likely 
to operate without the contact clearance procedure than NOSB units.  So it 
would seem to be elapsed time since last use more than absolute age that 
determines the likelyhood of working on power up.

BTW, yesterday I was in the neighborhood so I dropped by the place where we 
found the receiving antenna multicouplers, but although they let me prowl the 
aisles, they didn't have anything radio related.

In a message dated 6/2/2004 10:07:04 AM Central Daylight Time, 
gl4d21a at juno.com writes: 
> I recently reassembled a GE Progress Line mobile radio from 1954 for a
> vintage police car restoration.  It uses the dual interruptor vibrator,
> Mallory 1701 or equivalent.  Based on my previous experiences with
> vibrators, I hardly expected to find an operational one, but the first
> three I pulled out of the vibrator stash all vibrated on initial
> application of power.  I did not try to decipher the date codes on them,
> but they have been in dead storage for at least 20 years, so not all
> vibrators die in storage from sulfur contamination of the contacts.  I
> regret I did not record the manufacturers, but all 3 were different
> manufacturers.  I shipped all of them to the restorer along with the
> radio in case he gets serious about making the receiver work.
> 

Robert Downs - Houston
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