In a message dated 97-03-26 23:48:51 EST, you write:
<< Who sells that vaccummmm relay mod for the SB220??
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73 Robert W5AJ w5robert@blkbox.com
WB5CRG, VK5CRG, WB5CRG/VP2M & VP2E & WN5CRG !
>>
I don't know of anyone selling a kit, maybe someone on the reflector knows. I
did mine many years ago and without looking back at my notes here is what I
remember; The existing relay supply is used, two RJ1A's are used, their
coils are connected in series (spike damping diodes across both coils)with a
propper value dropping resistor. One RJ1 switches the output rf while the
other RJ1 switches the input rf AND the standby/operate bias. This is done
with .01 disc caps in series with the relay contacts with rf chokes coming
off the same two contacts and the other end of the rf chokes bypassed to
ground with another pair of .01 caps. This provides a RF path AND a DC path
through the same set of contacts. If I have not made this real clear I will
be glad to get a copy of the schematic posted on here in a day or so.
W6TG
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