Apache PTT Relay

[Glen Zook]

Just use a relay with a 6.3 VAC coil.  Run the "hot"
side of the heater ("filament") string to one side of
the relay coil.  Then run the other side to the pin on
the microphone jack that is used for push-to-talk.

Grounding this pin through the microphone will "key"
the relay.

It might be better to install a silicon diode (i.e.
1N4001, etc.) and add a good sized capacitor (like
maybe 1000 mfd or even higher @ 25 volts) to make the
relay run off of DC.  This should eliminate any "hum"
from being introduced into the microphone preamplifier
due to the wiring in the microphone itself.

If you use DC, then make sure and add a diode across
the coil in the reverse direction (cathode end of the
diode to the positive voltage and anode end to the
negative voltage source).  This is to prevent an
inductive "kick" when the coil is disenergized when
the microphone PTT switch is opened.

Glen, K9STH


--- lgrindel <lgrindel at MAIL.EV1.NET> wrote:

I would like to change the original "single pin" mike
plug for the "two pin" type used in the rest of my
Heath gear. I would also like to add a PTT relay.
Wiring the relay across the plate switch is pretty
straight forward, however I am confused as to how to
energize the relay using this two pin plug.

=====
Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco



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