Low Power Relay Switching - GE Phoenix
Using
a relay to remotely switch the radio from your control head is easily
accomplished A suitable Radio Shack SPDT relay (275-248A) with a
12 volt coil and contacts that will handle 10 amps will do nicely.
It's durable and small, and it can be epoxied to one of the
chassis side walls.
The first thing to do is to place a diode across the relay windings.
This diode is needed to clamp on the transient voltage spike that
will be generated by the electromagnetic core of the relay when the
relay is released. Without this diode, this voltage spike could
theoretically damage some of the electronic compoments either in the
radio, or in the control head. An ounce of prevention...........
Here is how the relay is wired up:
- Connect
one relay winding to the 'hot' side of the old ON / OFF switch.
The hot side can be verified by connecting your meter to the
radio's positive supply lead. Be mindful of the polarity of the
diode.
- Connect the 'swinger' contact of the relay to the positive supply, as well. This is a simple jumper on the relay.
- Connect
the normally open contact of the relay to both the other side of the ON
/ OFF switch and to the lead that will be powering the control head -
DB-25, pin 3.
- Connect the other end of the relay winding to the control head switch - DB-25, pin 17.
- When done, verify the connections with your meter.
DISCLAIMER
- - If you follow the steps outlined herein, you do so at your own risk.
I cannot, nor will not, be responsible for any possible damage to radio equipment,
personal property, to yourself or to others caused by modifications that you may make to
the radio as a result of your reading this.
The M/P controls
TRANSMITTING as well as receiving on many frequencies, suitable for a wide range of HF,
VHF and UHF needs. In the USA, TRANSMIT operation requires a license issued
by the FCC for
the class of operation intended. Amateur radio licensees must maintain strict
control over their equipment, preventing unlicensed operation within
the amateur bands, or outside of them.
Copyright 2000 - 2010 - K3JLS