Brodhead Pietenpol Association

Howdy, radio-frequency Pieters;

Trying to deal with an old Icom handheld with loose connections got too frustrating for me so I decided to buy one of Sporty's new handheld COMs, the PJ2. Just COM, nothing else, and it has headset jacks that accept standard aviation headset dual plugs, done. Well, not exactly- because I can't seem to find a way to make an external PTT switch work with it. First I tried a generic Telex PTT with velcro that mounts to the yoke or stick. It goes inline in the mic cord between the radio and the headset and inserts a jack for the external PTT. I tried this for push to talk and got a loud squeal in the headphones. Okay, I didn't like that velcro deal anyway and I have a hard-wired Ray Allen thumb button on my stick already, so I tried that and same deal, squeal. Must be the Lightspeed headset that I borrowed from a buddy to try for a quieter cockpit environment, so I tried my old tried and true Telex- squeal when I try to xmit with the external PTT. Okay, I have another PTT adapter that's worked just fine with the Icom but the plug on it is specifically for the Icom radio and won't fit the PJ2 so I contacted Sporty's to see if they offer a PTT adapter for the PJ2 since I must be doing something wrong. Nope. They want the operator to use the PTT button on the side of the handheld, I guess. This tells me that the microphone jack on the radio must not be wired in the conventional way, where a momentary-contact PTT can just shunt across the tip and sleeve to xmit.

I have plenty of jacks, plugs, and shielded wiring and can fab up an adapter if I thought that all I needed to do was to shunt across the mic tip and sleeve with an external PTT, but apparently that's not the case since it appears that inserting the headset mic plug disables something. I know I sound like a complete idiot, but I'm an electrical engineer and should know better so I'm blaming this on age. Anybody know what I'm doing wrong and how I can rig this thing up to work with an external PTT?

Oscar Zuniga
Medford, OR
Air Camper NX41CC, A75 power

I’ll start with the disclaimer that I am NOT an electrical engineer, and go to extreme lengths to avoid wiring projects! I ended up going with a Sigtronics intercom box/mixer for my PTT solution. My ICOM plugs into the Sigtronics box, my headset and PTT switch plug into the Sig box, and my front passenger will be able to plug in as well to facilitate communication beyond shouting and waving. (A stipulation of she-who-must-be-obeyed.) I used the Sigtronics intercoms pretty extensively in the bush planes I used to fly, where they got the snot kicked out of them, so I’m pretty confident it’ll hold up to the little Ol’ Piet. Mounting all of it is the next project, but my initial tests look pretty good.

OK, I'll take a look at that. I have an older Flightcom intercom and will see if that provides a solution, but I'm not hopeful.

-Oscar