SV-COM & SV-INTERCOM PTT Wiring Confusion

[TheFrisco]

So either I am not clear in my head anymore after wiring like a hundred wires or this is really confusing but how do I wire the PTT between the SV-INTERCOM-2S, the SV-COM-X25 and the PTT button on my stick?

I do own the intercom wiring harness but the MIC cable isn’t very clear, there is a blue wire I don’t know what to do with and how about the pilot and co-pilot runs? Do I need to go from the mic input to the stick and then to ground?

And yes I have the manuals, read thru it now 5 times, reviewed the full SkyView manual as well as the intercom manual and I can’t make sense of it.

Thanks!!!

 

[Rhino]

Do you have the pin numbers these wires go to on the DB25 connector of the SV-INTERCOM? 12 should be PTT to the radio, 10 should be PTT to pilot, and 16 should be copilot PTT. Pin 2 is ground for both pilots. There should be three pins on each PTT switch, PTT, MIC, and ground. You may not have a total of six wires though, depending on your routing, because the pilot and copilot use the same ground (the shielding on the cable). I don't know the pre-built wiring harness colors, but you should be able to determine all this with an ohmmeter. You should also be able to determine which pin the blue wire goes to if it isn't one of the pins above. In the meantime, I'll see if I can't find more info on the pre-built harness (with a background in avionics, I tend to build my own).

 

[Rhino]

If the blue wire ends up going to pin 7 on the intercom, that's your optional flip-flop switch to alternate between primary and standby frequencies on the radio.

 

[Rhino]

Found the harness diagram. All the blue wires are grounds.

https://www.dynonavionics.com/includes/guides/SV-HARNESS-INT_Harness_Guide-Rev_A.pdf

 

[TheFrisco]

Found the harness diagram. All the blue wires are grounds.

https://www.dynonavionics.com/includes/guides/SV-HARNESS-INT_Harness_Guide-Rev_A.pdf

Thanks super helpful!!!

 

[Rhino]

Glad to help. You know not to ground audio lines locally, right? Always use the ground (shielded) provided for in the harness. Using a local ground increases the possibility of interference. It's a good practice to do that with all grounds, audio or not, if a shielded ground is provided in the wiring.

 

[TheFrisco]

Glad to help. You know not to ground audio lines locally, right? Always use the ground (shielded) provided for in the harness. Using a local ground increases the possibility of interference. It's a good practice to do that with all grounds, audio or not, if a shielded ground is provided in the wiring.

Yes thanks for the reminder!

 

[smutny]

I have a similar question that has left me scratching my head. Upgrading an airplane, pulled out a 3rd party intercom and installing a Dynon SV-INTERCOM-2S. Airplane has a Skyview and Dynon Comm with the SV-COM-425.

Where exactly are the stick PTT buttons wired to? They went to the old intercom box, but I don't see on the Dynon schematics where the physical wires are connected.

UPDATE: Right after posting, Tech support called me back. The physical PTT wires are connected at the mic jack to the wires coming from the SV-INTERCOM-2S harness.

 

[Rhino]

Yeah, that's on the wiring harness guide I posted above but it depicts it as a table rather than as a schematic, so it's kind of hard to envision. But there is a simplified diagram on page 16-11 of the System Installation Guide.

 

[TheFrisco]

UPDATE - Yesterday I soldered in the phone and mic plugs, plus connecting the PTT wires to my push buttons ... Everything worked perfect. Thanks!!!