Inexpensive audio panel recommendations?

[Ed_Wischmeyer]

My RV-9A has a FlightTech ITC-402P intercom, and there are problems. Audio quality is good in Isolate mode, but in the ALL mode, there's lots of noise.

No, I have not debugged all the wiring to the copilot side, but the symptoms may indicate an internal problem.

The existing radio is a GTN650, hooked directly to the intercomm with 150 ohm resistors on the comm and nav signals, and with the G3X alerts coming through another resistor (they're not working yet). I thought it would be real cool to use a GTR200 as the intercomm, hooking up the GTN650 through one unswitched audio input with a simple toggle switch for, granted, limited but adequate audio panel functionality. I'm still looking for somebody else who appreciates this brilliant idea but have decided instead to take the hint and abandon the idea.

I really don't want to spend a bunch of money for an audio panel with lotsa features I don't need or want. Anybody got any good suggestions? Or does anybody have an SL-15 looking for a really good home?

thanks

Ed

[Mousse]

http://www.aircraftspruce.ca/catalog...audiomixer.php

I used the above in my -9 with good results.

[flightlogic]

Van's sells a blind audio mixer. It only makes sense to use a mixer if you are sourcing with two com radios though.
They are not really designed to solve intercom issues.... unless you go with a high end unit like PS that has intercom built in.

[BobTurner]

If you have some free time you can do what I did: build your own intercom, with mixers on the front end for as many inputs as you want or need. The most expensive parts are the knobs. I use the radio's volume controls as listen/don't listen. A single switch moves the mic and PTT between coms. Passengers have their own volume controls for radio and music, so if they want music and you don't, just turn your music volume all the way down. If you don't want to hear the passengers turn your intercom volume down. If they don't eant to hear you, turn your squelch to off.
I can send you the schematic if you're interested. Nothing hard, but some small parts to soldered

Bob

[vlittle]

http://store.makerplane.org/10-chann...r-mono-amx-2a/

http://54.162.78.90/redmine/documents/16

[Finley Atherton]

Originally Posted by vlittle

http://store.makerplane.org/10-chann...r-mono-amx-2a/

http://54.162.78.90/redmine/documents/16

I used the audio mixer above. Much cheaper than an Audio Panel and works very well.
My audio inputs are GTN 650, Icom A200, Skyview, Trio Propilot and a Sigtronics intercom.

Fin
9A

[flightlogic]

Ed, the kit version of that 25 pin mixer is only $75. But I don't remember if you are a homebrew electronics guy or not. It is small and detailed work, but easy if you have experience.

[Ed_Wischmeyer]

But I also need an intercom- the one I've got doesn't work well.

[Walt]

pretty hard to beat either of these:

http://www.aircraftspruce.com/catalo...ges/gma240.php

http://www.aircraftspruce.com/catalo.../pma5000ex.php

[rv7charlie]

Originally Posted by Ed_Wischmeyer

But I also need an intercom- the one I've got doesn't work well.

Before giving up on the existing intercom, can you supply more detailed info? Most simple intercoms tend to have one summing amp for all the mic inputs, with perhaps another amp for the radio input.

What kind of noise do you hear (hum, buzz, roar, etc). Does it do it with nothing plugged into either mic jack? With only the pilot mic plugged in? If you plug in both headsets (both mic & ear) and switch to isolate (where the pilot phones are quiet, right?), do you hear the noise in the passenger phones?

Charlie