The information for this adapter was floating around the internet, but it was vague and didn’t have any radio specifics. Plus I was unsure about PTT operation. The pin configuration was listed two different ways, so I created and confirmed the pin-out diagram below with my TM-V71A. If you have a different radio or want to connect other audio or cellular devices to your Peltor intercom (FMT120 or FMT200), it should be easy to re-configure. I covered connecting a GoPro Hero3 up to the Peltor in a previous post. Added note: PTT operation on 90% of radios involves grounding the PTT pin.
Cheap as can be: Order the $7 TA5FL female 5-pin connector. Lop off the end of a CAT5 or 6 patch cable. Cut up a 3.5mm stereo cable. Solder! Heat-shrink! Enjoy.
Going super fancy? You can add a separate illuminated PTT switch closer to the radio like I did, but don’t worry, the expensive PTT switch for the Peltor will still work as well (or in conjunction). Or just source an MP-101 and a normally open momentary switch for $5.
Buy it instead of building it: Something on this page from ruggedradios.com might work for you. I’m moderately sure that the wiring for the TA5FL is the same. No ham radio license yet? You could always just connect to your cell phone.