IFD440 Standby Monitor

It does not work and my installer tells me only an Avidyne audio panel has the functionality.

Can anyone confirm?

If you were referring to my comment, the cyan box, it just highlights the standby frequency that will flip into the active position when you hit the toggle switch. If you have more than one standby freq (you can have several) then whichever freq slot you touched last becomes the on deck standby freq. Very handy.

* Orest

While the IFD440 has an audio output for that standby frequency, you don't necessarily need to wire that up to get "monitor" functionality - a nice thing if you want to slide out an old 430 (that has no such wiring in its harness and tray) and replace it with the IFD440 without having to run more wires.  Most aircraft are equipped with a second com radio and an audio panel that has inputs from both the active IFD440 frequency as well as the active frequency from the second com radio.  If your audio panel is designed to present both audio signals to the pilot in ways that make it easier to decipher multiple speakers, you won't need to run any additional wires from the IFD440.  For example, my audio panel allows me to select to hear "both" (using volume on one to override the other if I want - the old way of doing things), "monitor" mode (which cuts off audio from the second com while the IFD440 is receiving a com transmission), or third, hearing the IFD com in the left ear and the second com in the right ear.

In other words, you don't always need to wire up the IFD440's monitor wire to get the "monitor" capability you want.

Now, that's interesting. I think that is what my installer was talking about. He said the monitor function was from the IFD440 and the audio panel had nothing to do with it. But I don't see how. If nothing gets wired and the monitor function interrupts the #2 input, how does that works? If two radios are connected to the audio panel, I select both, I can listen to both. But how will the audio panel know to interrupt #2 if nothing was wired to it? How would I even control that from happening when both radios are monitored? 

That has not been my experience, Catani.  There is no automatic muting.  The IFD simply plays both audio at the same time, all the time.  I have to manage them with differential volume.  As a matter of fact, if the volume levels (as observed on the AUX page) are the same, the Monitor audio is actually louder at my audio panel.  So I keep the standby/monitor audio level lower than the Com audio level.

My audio panel does have a "priority" mode, similar to what Catani describes.  But since I also have my standby monitor audio connected, I can play with three "radios" at once.

As a matter of technique, I manage the audio with volumes rather than employing the priority/muting functions in the equipment.

David Bunin

Thanks for the tip, I just got my PMA450A yesterday.  I had turned up the #1 switched input on the audio panel while troubleshooting because I wasn't hearing the audio.  They found a busted pin and moved it to the #3 slot, but I didn't think to recheck that volume; I bet it's still set at midrange for #3 (now the standby monitor).  I'll turn that up tomorrow and see how it works.

Thanks,

Jayson