Connecting intercom to video camera

[Don Jones]

Thought I might ask the electronics wizards how to tie the audio panel output into my video camera. Can I build a cable to take the audio out of one of the rear seat headset jacks and connect it to the mic input of the camera? Will impedence matching be a problem? Thought it would be neat to be able to hear something besides wind and engine noise. I figured I could always take a small mic and put it in my headset, but it would be nice to just be able to plug the thing in.
Don

 

[gismo]

Thought I might ask the electronics wizards how to tie the audio panel output into my video camera. Can I build a cable to take the audio out of one of the rear seat headset jacks and connect it to the mic input of the camera? Will impedence matching be a problem? Thought it would be neat to be able to hear something besides wind and engine noise. I figured I could always take a small mic and put it in my headset, but it would be nice to just be able to plug the thing in.
Don

This can be done quite easily. Impedance matching will not be an issue, the two issues are signal level and noise.
the level on the headset jack is close to what's called "line in" on a recorder and will have to be attenuated drastically if you feed it to a microphone input. If you camera has a "line in" (many do as this allows connecting a wireless mic) I'd try a direct connection to that from the headset jack. If all you have is a "mic" input, then a pair of resistors configured as a voltage divider will solve that problem. I'd start with something like 1000 and 100 ohms for an 11 to 1 reduction.

As to the noise issue, as long as you don't power the camera from the airplane's battery, you should be OK. If that's a requirement, you will probably need an isolation transformer in the audio feed, something you can get from Radio Shack albeit with the wrong connectors on it.

If you're not handy with wiring connectors, resistors, and transformers, it may be much simpler to go with the small microphone like a tie clip model inside one of the earcups of the headset you (or a passenger) are wearing.

 

[ErikU]

This is what I did, and it works great. Go to an avionics shop and buy a headset plug, the kind you can solder your own wires to. Go to Radio Shack and pick up an RCA male plug you can solder to, and get an attenuating adapter that goes from RCA to mini (this is a little red adapter that is designed to turn line level to mic level). Solder a length of good quality wire from the headset plug to the RCA connector, and then use the adapter to go right into your camcorder.


Or...

Get a little mic and put in in one of your earphone cups. No soldering required!

 

[Don Jones]

Thanks Guys,
I went to RS, they had a 6 foot attenuating dubbing (90db) cable with 1/8" jacks on it, got an adapter from the headset plug to the 1/8" connector, plugged it into the headset jack on my handheld and into the camera to test it and works perfectly, just plug and play no soldering required.
Don

 

[gibbons]

Do they have anything with a Bose interface jack?

Chip

 

[Don Jones]

Do they have anything with a Bose interface jack?

Chip

I wish I had the bucks to own one to be able to tell ya. I kinda doubt it.
That one is on my list. I gotta birthday coming up soon, ya'll wanna donate
to the cause?
Don