[BC] BT-20-A

[Ron Youvan]

> I am restoring an old G.E. 250 watt broadcast transmitter (BT-20-A) for
> Amateur Radio use and I need some advice on the Power-Failure Reclosing
> Coil.  It's a G.E. catalog #CR2820-173IC.  It's a quick close - 3 second
> time delay open type relay.  If any of you guys have worked with one of
> these old timers in the past and can remember much about their operation I
> would sure appreciate some education.  It appears to be complete and the
> coil energizes, closing the contacts, but it never reopens until I reset it
> manually.  For all I know that may be the way it's supposed to work.
> However, according to the manual it should reset (contacts open)
> automatically in about 3 seconds.

> Any help will be greatly appreciated.

   I don't know the exact relay, but in an odd place there
should be a screwdriver driven adjustment to set the time,
about 3/16" in diameter, a shaft with a slot like a screw
head.
   I was told these are pneumatic, but I never tore one apart,
so that is hearsay.  If so the "rubber" parts may be rotten
or have been torn.  (I have seen lightning do this!)

   These can be replaced with a modern R-C timer relay or you
can make one with a DC relay and capicator/s driven with a DC
power supply.   (big electrolytic)
-- 
    Ron  KA4INM - My Florida property tax is 7 times what it was
                  3 years ago with no change on my part. OUCH!