Now that I got off on this tangent on intercom audio interfaces,
I'd suggest something like this for what you want (similar to previous
post):

Headset Plug Tip|----\/\/\/-----|====== Left/Right to cam
| 680 \
| / 82
| \
Headset Ground |---------------|------ GND of cam

That'll load it so it looks something like a real headset, but cut
the voltage down by a factor of 10 or so. If you don't want to load your
intercom, make it 6.8K and 820 Ohm. Adjust the 82 (or 820) size to
plus/minus a factor of 3 or so if you need to adjust the volume.

My guess it that'll do it.
-Cory

Dylan Smith wrote:
: On Mon, 14 Jul 2003 21:39:49 GMT, Bonanza Man wrote:
:is there an adaptor that'll take the head-set
:audio-out of an airplane intercom into
:a jack that can be put into a standard
:microphone jack in a video-cam.

: I made one the quick and dirty way for my big trip.

: All I did was stick a big resistor in-line with the audio (actually a
: minature potentiometer, so I could fiddle with it). I initially underestimated
: the resistance needed (I thought it might be on the order of 5k ohms,
: I ended up using IIRC a 470K potentiometer maxed out). I just soldered
: the pot to the pin for the intercom jack tip, then the wire to the other
: end of the pot. The potentiometer fits inside the jack plug's cover,
: and a bit of heat-shrink rubber makes sure the exposed contacts don't touch
: the signal ground's pin. So you have


: intercom jack

: /-|============| 470K |---------------------left channel
: / |-----------------/\/\/\--|---------------------right channel stereo
: \ | | jack
: \_|============|------------ signal ground --------------------

: It worked well. All the parts can be picked up at Radio Shack. I just
: butchered a stereo jack extension cable for the camera side, and soldered
: it into a nice screw-together large jack for the intercom. It is quick
: and dirty; I think the proper method is to have some form of impedence
: matching transformer, but I don't know whether such a beast exists that's
: suitable for intercom - camera.

: I also made a video camera stand which could be quickly attached to and
: released. It was basically a shaped polystyrene block (shaped to the
: curvature of the glareshield), which was velcroed to the panel. The camera
: was in turn velcroed to the top of the polystyrene block. It stayed on
: even during some of the severe turbulence I encountered crossing the Sierra
: Nevadas (multiple negative-g bumps which made my charts almost hit the
: roof) but was quick to pull off by hand. Make sure you don't site the camera
: too close to the compass - I did some testing to see where I could place the
: camera without causing the compass to move.

: --
: Dylan Smith, Castletown, Isle of Man
: Flying: http://www.dylansmith.net
: Frontier Elite Universe: http://www.alioth.net
: "Maintain thine airspeed, lest the ground come up and smite thee"


--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************