I'm constructing a vacuum/reed relay QSK T-R system in my converted SB-220 6m
amplifier. I'm using two Kilovac HC-1 vac relays for the input and output RF
switches and one small RGS-6396 DPDT (SPDT/RF, SPDT/aux) reed relay purchased
from MGS (http://www.mgs4u.com/RF-Microwave/RFrelays_misc.htm) to switch the
bias voltage between operating bias (TX) and cut-off bias (RX). (Not using the
RF part of the reed relay.)
According to everything I've read, coil polarity is important on (most?) DC
reed relays. Using three 9V batteries in series as a power source just for test
purposes, the little relay appears to operate reliably using either voltage
polarity across the coil -- but I haven't hooked it up to a scope yet to see if
there is a difference in speed.
There is no +/- indication anywhere on the relay body -- and according to Allen
Bond of MGS, polarity on this particular relay probably doesn't matter. He said
that in his experience, all polarity-sensitive reed relays are clearly marked
with +/-. However, there is a schematic diagram of the relay printed on the
body, and in this diagram, one terminal of the solenoid coil is represented by
an unfilled circle, while the other terminal is represented by a filled circle.
I'm wondering whether this might be indicative of coil polarity.
Does anyone on this list know if this is true for this particular MGS-supplied
relay?
Bill W5WVO
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