Push-To-Talk Wiring

[Dave S]

Got a question......what kind of wire have you used to connect a stick mounted PTT switch to the radio/intercom harness?

Will shielded Tefzel wire hold up to the constant flexing between the stick and wherever it is attached to the fuselage?

The spiral phone wire I originally used for the flexing portion of the wire run appears to be giving up.

Thanks,

Dave S
KF7 Trigear - Flying
912ULS Warp Drive

[Av8r_Sed]

I used the shielded Tefzel allowing for a somewhat large bend radius where the movement is. It's been good for one season so far.

[Dave Holl]

That's what mr Boeing uses!!!

[Dave S]

Sounds good to me......Think I will be ordering up some shielded wire.

BTW...Av8r...how big of a diameter loop did you decide on?

Dave S

[Dorsal]

I used regular 22 gauge Tefzel wire (no shield) with a generous bend. There is no signal on a PTT line so shielding is not necessary from an electrical point of view though may offer some mechanical advantage.

[Av8r_Sed]

I have a radius of about 1 1/2 inches. I secured it with wire ties and put the stick through it's full range of motion while making small adjustments.

I used shielded on the PTT because the long line make a nice antenna when the buttons aren't pushed. I didn't want to channel noise right to my radio / intercom connector.

[jiott]

I used 22 ga. non-shielded wire, but also put on some strain relief heat shrink in some critical spots because of the continual movement.

[jrevens]

I agree with Jeff. The only reason that you might want to use something a little larger than 24 GA, for instance, would just be for a little more robustness since this wiring will be subject to more movement than most of the other wiring in the aircraft, IMO. I believe I used 20 or 22 GA.

[Maverick]

Anyone got a good picture of how you wired the PTT?

Also, did you run the ground back to the common ground, meaning one would need to run two wires through the control stick mechanism?

I was planning to use 20ga wire but could use 18. What's the recommendation on wire size.

[jrevens]

You’ll need two wires. 20 ga would be plenty big. There is no current to speak of on this circuit.