Aircraft Intercom

[j_dunavin]

Has anyone ever tried to make an intercom? Or at least a mic, with headphone circuit?
Since I am building my own aircraft, why not build my own intercom?
here is a link the to the aircraft:
Pietenpol Air Camper - Wikipedia, the free encyclopedia

And here is a link to an intercom from David Clark:
David Clark ISOCOM
The link to the manual has a schematic at the end.

I took a look at it and the parts, and aside from one NPN transistor, everything can be found on Digikey for cheap. And I found the replacement for that one NPN.
I duno could be a fun project.
The plan so far is to go with WW2 style cloth helmets with throat mics.
Like this:
Bell's Aviation, LLC: Army Air Corps, US Navy, and USAF Flight Gear, Clothing, and Equipment
Bell's Aviation, LLC: Army Air Corps, US Navy, and USAF Flight Gear, Clothing, and Equipment
Bell's Aviation, LLC: Army Air Corps, US Navy, and USAF Flight Gear, Clothing, and Equipment
I think I could use this schematic, and add a copilot volume and squelch control.
Any thoughts?
Would either have to wire PTP or make my own PCB....

 

[SemperFi]

Very cool project, an intercom. The airplane gives u a decent alibi even my wife can't argue around.
Since the a/c is from before transistor, u ought to build a tube set. Or even better build horns u can talk (yell) straight into.

 

[j_dunavin]

HAHA horns would be cool!
The plans, of course do not call for any electrical system, but we at least want the convenience to talk to each other, and have a hand held transceiver for communication to gnd.

 

[epitaxial]

Intercoms for homebuilt A/C

It the intercom is connected to the panel mounted avionics, I would only use a Sigtronics or Isocom. They have aux inputs and outputs as well. Thes will handle A/C conditions, and won't interfere with tower communications.

A DIY intercom for passengers and background music would be a great idea too, especially with a pair of lightweight noise cancelling hedphones, such as one of the Headwise projects.

 

[Speedskater]

What do motorcyclists use when riding with a backseat passenger?

 

[j_dunavin]

probably a very similar deal.
An aircraft intercom though, allows a transmit button, to pass your mic through to a transceiver, and also allows the transceiver's side tone to back up into the intercom and into your headset.

 

[dangus]

Are there any regulations to obey regarding electronic devices in aircraft? There's not much point in building an intercom if someone with a clipboard is just going to tell you to tear it out again.

 

[j_dunavin]

It depends.
For an experimental aircraft, it does not matter, Except when you are regarding electronics that deal with ATC. Those would be the transponder, ELT, nav, and comm radios, ect. Since those devices are over the air, the FCC also has a lot to deal with that.
The intercom is not regulated, at least for an experimental aircraft, because even if you loose that devise you could still communicate with ATC through your radio.
Another interesting fact, is if you look at that schematic, when you turn off the intercom the off switch will take the radio input and bypass it straight to your phones.
A regular aircraft is totally different, when it comes to "approved" electronics.
Everything has to be tested, and come with a piece of paper saying so. See then it's trackable.