[AMRadio] K5 and delay relays

VJB wa3vjb at yahoo.com
Mon May 14 07:48:10 EDT 2007

At least you have a fairly conventional delay relay,
that Amperite. They seem pretty common to find in
hamfest junk boxes.  I have a chart explaining the
nomeclature if you need it to determine normally
open/closed and the time specification.

Try finding what I've got in the Collins 300-G (ca.
1946-1952)-- a spring loaded wind-up gear driven set
of relay contacts much like a clock.  When you turn
the transmitter OFF a set of relay contacts closes,
triggering a motor on a gear reduction that winds up
the "clock" to get it ready for the next time the
transmitter is "started," as they say.

Upon pulling the start switch, the low voltage /
filament circuits ignite, and you can hear the timer
ticking down to when it reaches the bottom of the
spring load. It comes to rest, keying a set of relay
contacts that engergize the high voltage circuits.

Amazing stuff, very mechanical.


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