Transceiver PTT switch

[RayPierce]

Does anyone have a schematic diagram for a PTT switch cable that interfaces an ICom IC-A20 radio and Blissom mic/headphones?
The radio and headphones I bought came without the PTT switch and cable.
I can buy the cable from Comtronics but I would like to make something different. I just need the schematic.

[Chuck Irby]

Ray, I wish I could help, as I recently went through the same thing and could never come up with a schematic. I finally got Bruce Tess to make up a cable for me to use with my PTT that is built in to my stick grip. You can call Bruce @ 715-366-7095 if you can't find the schematic. In fact, Bruce can probably provide you with a schematic.

[Caribean_gyro]

I Feel buying is cheper on the long run. I used the PRR adapter from Icom, better and also had an amplifier in it. But if you want to build go to Radio shack buy the plugs and check jumping to ground your PTT. I will check at my hangar to see if I can drwa a picture of this .
CHuckP

[Phil W]

Ray,
Go here...... http://www.aerialpursuits.com/
This site has a few ptt circuits, none for the A20, it does have the A3, A4, A22, A22/A5... it may give you an idea where to start, or contact them to see if they have the details you want. look under Communications
Phil W

[RayPierce]

Phil

I found the schematic for the A20 right away!
I'll be dropping by Radio Shack tomorrow for the parts I need.


Thanks again.

[Al_Hammer]

Also checkout this Sigtronics adapter
PN 900071 sigtronics
http://www.sigtronics.com/air/accessfr.html#handheld%20radio%20adapter%20cables


This is how the Sigtronics headset adapter
works. The PTT switch is wired in series with the microphone, so
that when the PTT is closed, microphone current is drawn, and the
transmitter is keyed. The "ICOM PTT" uses the same method. The
(shielded) wiring used by Sigtronics (and myself) is as follows:

( T = tip, R = ring, B = barrel of jack connectors )

Headset, T _________________________________ T ICOM IC-A20,
LARGE jack B _________________________________ B 3.5 mm plug
(earphone) (speaker)

PTT
Headset, T __(key, unused) ______o o________ T ICOM IC-A20,
SMALL jack R ________________| (pwr, unused)__ R 2.5 mm plug
(mic/key) B _________________________________ B (mic)