Garmin 430 intercom

[PeteP]

Does the Garmin 430A (non WAAS) have a built in intercom? I see a intercom mic high and low on J4002 and was not aware that the 430 had a built in intercom, or is something else?

[Mark Dickens]

No intercom included...those pins are for the mic input to the com radio that IS a part of the 430

[Veetail88]

The GMA240 in this diagram is the intercom.

[SteinAir]

Hi Pete,

You'll notice that no matter which radio you eventually choose, they all have at least three things (Also, "Hi" typically refers to a signal and "Lo" typically refers to a ground):

1) Mic Audio Hi - This is the sound from your microphone to the radio and what the radio eventually transmits over the antenna.
2) Comm Audio Hi - This is what you hear in your headset or what the radio receives - what you hear from the radio.
3) PTT / Mic Key - this is the Push To Talk, which engages the transmitter and allows said Mic Audio information to be transmitted.

Some will have varying degrees of additional info (if it's a Nav/Comm you'll likely also have a "Nav Audio Hi", or a terrain warning, etc..).

Typical radios will have between 3 to 10 wires dedicated to those things. They all eventually correspond to arms on the headset/mic jacks, either through an intercom, audio panel, etc.. (both internal and external).

Radios with internal intercoms will have similar outputs, but maybe more. If it's stereo, you'd have an audio L and audio R, etc..

Cheers,
Stein

[PeteP]

Thanks for the input. The reason I brought it up is that the G430 J40002 connector has inputs for com mic audio high and low as well as intercom mic high and low. Don't understand the function of the intercom inputs.

[BobTurner]

The 430 series does indeed have an "intercom". Basically it is a hot mike (no squelch) system which cannot handle more than one mike at a time.
Notes from the installation manual (my paraphrasing):
"use only if no other audio panel/intercom is available"
"use external relays to assure only one mike at a time is present on the input"

You could use this input, along with intercom push to talk switches for each person, to make a very basic intercom system.

[RV8iator]

It's still smoke, mirrors and PFM to me. Thank you to those of you that make it all work.

Give me a wrench.

[PeteP]

You are correct. I got my hands on a G430 circuit diagram this morning and there is in fact a hot mike circuit in the design. It is of very limited usefullness but does exist.