Originally Posted by nakman
I learned today from Motocomm that FGL-559 would be the correct system for your Yaesu VX-7R. The VX-3R would be the FGL-558 system. the difference is the plug that goes into the radio, one is waterproof for the VX-7, the other not so much. I went ahead and ordered the kit, with the plug for each HT... will do a little documenting once it all gets here.
The connector for the VX-1/2/5 has the same pin out as the VX-6 and VX-7, although the connectors are slightly different. The VX-7 has a screw-in base that retains the waterproofing which means its body is narrower. If you use an accessory designed for the VX-5, for example, you have to shave the connector body to make sure it sits down far enough into the VX-7 connector, otherwise the plug does not insert far enough and you can short VCC to the shield or mic.
I personally cut off the VX-5 type connector and solder on the correct one, you can get them from Mouser and other places, both with and without a pigtail. It's also possible to use 4-conductor phone connectors with molded bodies designed for iPhones.
FWIW, I didn't dink with the PTT and just used VOX on the VX-7, which is why ambient wind noise is a major concern for me.
Kobiconn 4-conductor 3.5mm plug:
Kobiconn with molded pigtail:
Argent's raw cables (slightly cheaper than buying a CT-91 to cut up):
Tip - Mic/PTT
Ring - Data
Sleeve - GND
Tip - Speaker
Ring - NC
Sleeve - GND