Headphone receptacle wiring and pin outs for GNC 250. Educate me please.

[terry.mortimore]

Hi gang: I’m trying to wire a set of headphone receptacles to an old Garmin GNC 250. I wired the receptacles in parallel together and have a shielded three conductor wiring running to the radio. At the time I thought I used a diagram from Stien to wire the receptacles, but now I’m not sure.

I have the white wire going to the tip of microphone receptacle (small hole).
I have the orange wire going to the ring (middle section of plug) of the headphone receptacle (large hole)
I have the blue wire going to the barrel of headphone receptacle.

I have the Orange wire connected to pin #2 (mic audio Hi)
I have blue wire connected to #3 pin (mic audio Lo)
I have white wire connected to pin #5 (Comm audio Hi)
I have the shielded braid going to #25 pin (ground)

It’s not working and I’m struggling to figure it out.
First does someone have a diagram for wiring up the receptacles if I don’t have it correct?
Secondly can someone help me with the pins I should be using on the radio? The installation manual I have for the radio is not much help in this regard.

The push to talk is coming from the top of the stick and that is working.

Thanks in advance, Terry

 

[BobTurner]

Okay….
Your mike wiring (Hi and Lo) should be okay (pins 2 and 3) with pin 2 going to the ring terminal and pin 3 to the ground terminal. The white wire should not go to the tip of the mike, it should go to the tip of the phones. You need to run a wire from pin 6 (audio lo) to the ground terminal on the phone jacks. This will work for mono. If you have stereo phones run a short wire from the tip terminal to the ring terminal, but then do not plug in mono headphones, everything will short. It’s okay to parallel two headphones but poor practice to parallel two mikes. Run the ring connections from the mike jacks thru a 2 pole single throw switch to select one, or the other, mike, that goes to pin 2.

 

[terry.mortimore]

Woot, Woot, success! Thanks Bob, I redid the wiring as per your suggestions. Works great now! Ground read me 5 x 5!

Really appreciate the help, beers on me at Oshkosh.

Terry