recording from intercom system

[Nobody]

I would like to record, from the intercom system of a typical GA plane
(Cessna), to an off the shelf digital audio recorder. The question is, how
do I go from the intercom system to the 'Mic' jack of the recorder....
without damaging either? I presume I need more than just a 2.5mm adapter
for the intercom system???

Thanks in advance

-RM

[Michelle]

Nobody wrote:
> I would like to record, from the intercom system of a typical GA plane
> (Cessna), to an off the shelf digital audio recorder. The question is, how
> do I go from the intercom system to the 'Mic' jack of the recorder....
> without damaging either? I presume I need more than just a 2.5mm adapter
> for the intercom system???
>
> Thanks in advance
>
> -RM
>
>
You will need something to attenuate the signal.
Should be available at radio shack....
1/4 inch on one end and 3.5mm on the other, then 3.2 to 2.5 adapter.
Was red on the 1/4 end.
Michelle

[Jon Woellhaf]

RM,

I use a Radio Shack 1/4 inch male mono phone plug to two 1/4 inch female
phone jacks splitter (RS #910-0791) and plug that into the headset jack. I
plug my 1/4 inch headset earphone plug into one jack of the splitter. I plug
a three foot long 1/4 inch male phone jack to male RCA plug cord (RS
#970-0916) into the other jack of the splitter. I plug a female RCA to male
3.5 mm 40 dB attenuator (RS # 910-0889) into the cord and plug that into my
recorder. If your recorder needs 2.5 mm you get to add yet another adapter.
It's not elegant, but it works. I plan to neaten it up some day by adding a
3.5 mm jack to the panel and wiring it through a simple attenuator directly
to the headset jack.

Caution: Radio Shack has an attenuator cable that has a 1/4 inch phone plug
on one end and a 3.5 mm plug on the other. It looks like the perfect
solution, bit it won't work well (if at all) because it's designed for an 8
ohm system and Cessnas expect to drive a minimum load of 38 ohms, according
to Jim Weir -- and he knows all about this stuff.

Jon

"Nobody" > wrote in message
...
>I would like to record, from the intercom system of a typical GA plane
> (Cessna), to an off the shelf digital audio recorder. The question is,
> how
> do I go from the intercom system to the 'Mic' jack of the recorder....
> without damaging either? I presume I need more than just a 2.5mm adapter
> for the intercom system???
>
> Thanks in advance
>
> -RM

[Newps]

I fed the intercom and radio into my Sony camcorder by using a regular
patch cable with mini stereo jacks on either end. On the airplane end
you get an adapter for the regular stereo jack. No attenuation needed
and it sounded great on the tape.



Nobody wrote:

> I would like to record, from the intercom system of a typical GA plane
> (Cessna), to an off the shelf digital audio recorder. The question is, how
> do I go from the intercom system to the 'Mic' jack of the recorder....
> without damaging either? I presume I need more than just a 2.5mm adapter
> for the intercom system???
>
> Thanks in advance
>
> -RM
>
>

[GeorgeC]

If you don't want to build your own patchcord, Aircraft Spruce Pilot Shop has
one. Patchcord Cockpit Voice Recorder, P/N 6-13-01456 $24.95

On Thu, 30 Mar 2006 18:58:14 -0600, "Nobody" > wrote:

>I would like to record, from the intercom system of a typical GA plane
>(Cessna), to an off the shelf digital audio recorder. The question is, how
>do I go from the intercom system to the 'Mic' jack of the recorder....
>without damaging either? I presume I need more than just a 2.5mm adapter
>for the intercom system???
>
>Thanks in advance
>
>-RM
>

GeorgeC

[Dylan Smith]

On 2006-03-31, Nobody > wrote:
> I would like to record, from the intercom system of a typical GA plane
> (Cessna), to an off the shelf digital audio recorder. The question is, how
> do I go from the intercom system to the 'Mic' jack of the recorder....

The right way to do it would be some kind of impedance matching
thingamajig.

The quick and dirty way of doing it is by going to somewhere like Rat
Shack, get a 1/4 inch jack, some cable, and the right jack for the
recorder (probably 1/8th inch). Put a 470K ohm resistor inline. That
seems to attenuate the output level of the intercom such that it will
work with a Sony Digital 8 video camera. It's worked very well for me
(the resistor lives inside the 1/4 inch jack that plugs into the headset
connector on the intercom).

--
Dylan Smith, Port St Mary, Isle of Man
Flying: http://www.dylansmith.net
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de
Frontier Elite Universe: http://www.alioth.net

[Dylan Smith]

On 2006-03-31, Newps > wrote:
> I fed the intercom and radio into my Sony camcorder by using a regular
> patch cable with mini stereo jacks on either end. On the airplane end
> you get an adapter for the regular stereo jack. No attenuation needed
> and it sounded great on the tape.

That's interesting to know - I found I had to put a 470K ohm resistor
inline to stop it from horribly distorting on the recording on my Sony
camcorder (it's possible that more recent camcorders figure out how much
to attenuate the signal themselves).

--
Dylan Smith, Port St Mary, Isle of Man
Flying: http://www.dylansmith.net
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de
Frontier Elite Universe: http://www.alioth.net

[FLAV8R]

I have read most of the other solutions on this thread and the one I use I
got right here on this NG a while back.
It is as simple as buying a lapel mic and dropping it inside your headset
and it records everything you hear.
I have had no distortions or problems with my digital recorder or my Sony
digital 8 video camera.
Well I did have one problem, I forgot to turn the mic on one time and it
made for a very quiet video.

David
KORL

"Nobody" > wrote in message
...
>I would like to record, from the intercom system of a typical GA plane
> (Cessna), to an off the shelf digital audio recorder. The question is,
> how
> do I go from the intercom system to the 'Mic' jack of the recorder....
> without damaging either? I presume I need more than just a 2.5mm adapter
> for the intercom system???
>
> Thanks in advance
>
> -RM
>
>

[Tauno Voipio]

Andrew Sarangan wrote:
> Nobody wrote:
>
>>I would like to record, from the intercom system of a typical GA plane
>>(Cessna), to an off the shelf digital audio recorder. The question is, how
>>do I go from the intercom system to the 'Mic' jack of the recorder....
>>without damaging either? I presume I need more than just a 2.5mm adapter
>>for the intercom system???
>>

> I did this with a series resistor to attenuate the signal. Connect a
> trim pot resistor and change its value until you get an undistorted
> recording.

Still better: Connect the resistor in a potentiometer connection,
CCW end to common (ground), CW end to signal source and slider
to output. Take the low side of output from common.

--

Tauno Voipio (CPL(A), avionics engineer)
tauno voipio (at) iki fi

[Thomas Borchert]

Flav8R,

> It is as simple as buying a lapel mic and dropping it inside your headset
> and it records everything you hear.
>

That is indeed a great solution. One added benefit is that recording from
the intercom will get you only voice, and very little engine sound. Now, for
some purposes that may be ok, but for a fun trip video it is way too
sterile, you want an even mix of engine noise and the talk going on, just
like the people on board get it - and that's exactly what you get with a mic
inside an earcup.

--
Thomas Borchert (EDDH)

[Thomas Borchert]

RST,

> turning the squelch on the intercom off
>

That's not what I would consider "less hassle" ,-)

--
Thomas Borchert (EDDH)