I want to connect ir out of the mrf350 to a vanco hdmi over cat 6 extender with ir.
The emitter suppled with the vanco is TRS. The input on the transmitter is TRS and with my meter looks like Tip and Ring are connected. It wants 5 volts input. I tried connecting a 3.5mm stereo cable from the mrf 350 to the vanco, but the emitter doesn't appear to work.

I am thinking I need to make a custom cable that is TS on the mrf side and TRS on the vanco side, but I don't know what to do with the 3rd wire.

Any suggestions would be most appreciated.

Thank you,
Ian_S

First off which Vanco device are you using.

Assuming a lot about your setup and not a final answer but I'd "desk check" it by using a standard IR emitter on MRF350 attached to/near IR receiver (kludge but is great way to test) that is plugged into the Vanco input side. On the Vanco output side I'd use the Vanco supplied emitter and confirm it all works.

If it works, the two possible issues are voltage and polarity. Polarity is a simple fix. Voltage differences will require you to leave the kludged connection in place or find a opto-isolated cable -- the one I've used is made by Global Cache to connect Xantech to their devices but I've used it between multiple pieces of equipment.

Thanks for having a look at my post and replying.
I am using a vanco 280592. Ir receiver into vanco tx near mrf works.
I guess I could leave that...It works as designed but i would prefer the cleaner direct connection from the mrf into the vanco. I called vanco but they couldn't tell me how the trs is wired...

No pictures I could find shows the supplied cables. It is typical that the IR Receiver supplied by Vanco will be a three wire device and my other hint was you mentioned using a stereo cable. That means the vanco receiver requires a signal, ground, and power connection but as you know a IR emitter only needs signal and ground.

For this to work as direct connection, you'll need to confirm the voltage output of MRF and voltage input of Vanco are same. If they are, you can cut a stereo cable at a point where it can be nicely recoupled and locate the signal and ground with a mutimeter and only reconnect those wires. Depending on internal connect you may have to double connect sleeve and ring on MRF side to the same wire. Signal is usually tip on both ends (typically) and the (ring & sleeve) on the MRF end would be connected to either the ring or sleeve on the vanco input.

Unless it is ugly or problematic, I'd leave as is and maybe wrap wit h black electrical tape.