Portable 4 place intercoms-roll your own?

I was looking at these, in anticipation of getting my ticket soon (I
hope!). The prices seem to be all over the board. Many seem to have an
add on module for use with 4 passengers.

I certainly don't know how to design electronic stuff, although I can
read a schematic and build something from one, so how hard is it to
build your own portable setup for a renter? a battery or running off the
planes 12V socket to boost the signal somehow (I guess-many units seem
to require one or the other). A bunch of jacks for the headsets, a
couple of plugs for going into the pilots com jacks. Switches for
all/pilot-copilot isolate/pilot isolate (sounds like a mess of wiring in
their), maybe auxilary inputs for CD players and cell phones.
Hmmm...how do you wire in the copilots mike when the plane has built in
PTT switches?

Starting to sound more complicated than I thought.

John

Hi John, I was looking into this a year ago. If you search the net you
can find schematics for a 4 person aircraft intercom with aux in.
However, I could not find PCB software able to deal with all the chips
and routing, and flying wire connections are not really a great idea in
a shaky cockpit. Parts for a mono version cost around $60 plus PCB
printing, etc.
If you have the software or patience to build your own board then it's
an option, otherwise you might want to consider what RST or Sporty has
to offer.

My flight instructor carries two pairs of splitter cables. I wish I knew
how to wire them because they look quite simple. He says that he bought
them at a pilot shop for about 50 bucks. Essentially you plug one into the
cockpit, and that splits into two. If I run across them for sale on the net
I will respond back.

--
John Huthmaker
PPL-SEL P-28-161

http://www.cogentnetworking.com
"John T" wrote in message
...
I was looking at these, in anticipation of getting my ticket soon (I
hope!). The prices seem to be all over the board. Many seem to have an add
on module for use with 4 passengers.

I certainly don't know how to design electronic stuff, although I can read
a schematic and build something from one, so how hard is it to build your
own portable setup for a renter? a battery or running off the planes 12V
socket to boost the signal somehow (I guess-many units seem to require one
or the other). A bunch of jacks for the headsets, a couple of plugs for
going into the pilots com jacks. Switches for all/pilot-copilot
isolate/pilot isolate (sounds like a mess of wiring in their), maybe
auxilary inputs for CD players and cell phones.
Hmmm...how do you wire in the copilots mike when the plane has built in
PTT switches?

Starting to sound more complicated than I thought.

John

John,

My flight instructor carries two pairs of splitter cables.


Won't work for the mics...

--
Thomas Borchert (EDDH)

Thomas Borchert wrote:
John,

My flight instructor carries two pairs of splitter cables.


Won't work for the mics...

Works fine for the mics. I built a breakout box that parallels 3
mics and 3 headphones.

What DOESN'T work is a David Clark headset in the mix. The DC
uses so much power that it drops the bias voltage so low that
none of the other mics work. :-(

Best regards,

Jer/ "Flight instruction and mountain flying are my vocations!"
--
Jer/ (Slash) Eberhard, Mountain Flying Aviation, LTD, Ft Collins, CO
CELL 970 231-6325 EMAIL jeratfrii.com http://users.frii.com/jer/
C-206 N9513G, CFII Airplane&Glider FAA-DEN Aviation Safety Counselor
CAP-CO Mission&Aircraft CheckPilot BM218 HAM N0FZD 240 Young Eagles!

If you have links to this website (schematics with PCB layout), I could
use a CNC machine and route a PC board.

Or did you mean software to layout the circuit board?

John