Don Patrick

Don Patrick

Well Known Member
Hello folks,

I'm working on my harness tonight for the PMA5000 and the SL-40. Looking at the wiring diagrams for the SL-40, I have the Headphone (pin 14) going to COM 1 audio hi (pin 9) on the PMA 5000 and the Audio gnd (pin 13) going to com 1 lo (pin 10) on the 5000. That I get.

Looking at the Mic setup...Mic 1 (pin 8 SL40) goes to com 1 mic audio hi (pin 11 5000). The Mic gnd (pin 7 SL40 doesn't go anywhere on the pma5000, but the SL-40 manual indicates to ties it to the audio gnd (pin 13) which will go to pin 10 on the PMA5000. Those are 2 wire shielded wires.

The problem I'm having is the Txkey is on it's own and not shielded on the SL-40 manual and is supposed to go to the PMA5000 pin 12 com mic key where it is showing as shielded?

So, should I use a 3 wire shielded cable for the mic setup, tie the mic ground to the audio ground and go from there?

I love this stuff!!!!:rolleyes:
 
Yes, tie the mike ground to the audio ground.
The Tx key is just a dc signal. Unshielded wire should be fine.
 
If you have 3wire shielded, just use that.

I have the same setup with SL40 being Com2 on my setup. If you use the 3rd wire for the mike in that case, it just cleans up the wiring bundle a little. That's what I did. You'll get conflicting case ground instruction from the SL40 and PMA5000 diagrams. For me, using Stein's diagram, all shielded wires between the SL40 and PMA5000 were case grounded on the SL40. All PMA5000 shielded output wires to the ear and mike jacks were case grounded to the PMA5000. The other ends of all those shields are left open. I have a GTN750 as Com1, and it's also case grounded on the radio, not the PMA5000.
 
Awesome.

That`s just what I needed Wendell.

The way the IM is written it shows that all shields are to be grounded at the PMA5000...I`ll follow you`re lead and if Stein says it`s good, I guess it`s good!

Cheers,

Don
 
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