How does intercom handle two radio monitoring?

[infobomb]

Hi Dynon!

I see that the switch for the 2-radio solution determines where to route the PTT trigger but the radio audio selection is left to the user by adjusting each radio's volume control. I prefer to set my radio volumes and not mess with them.

Is it acceptable to route the two radio audio outputs (normally direct to pins 7 and 14) through two SPST push-buttons so I can select both, comm 1, comm 2, or none, as radio inputs? Will there be any undesirable side effects to this? I'd use lighted-switches to indicate on/off for clarity.

Thanks ,Neil

 

[dynonsupport]

Sure, you can do this, but this means you can only listen to one radio at a time. A big benefit of two radios can be the ability to listen to ATIS on one and the TWR on another.

A normal intercom or audio panel doesn't let you turn off the audio to your active com, and always requires one to be active. So, when you take off at a towered field and fly away, what do you do when you no longer want to listen to the tower who is chatting away to the local pilots? Do you turn down the volume, or do you tune to an unused frequency? You can do exactly the same thing you would do there with your unused COM with the Dynon intercom in order to silence an unused radio.

 

[infobomb]

Thanks for the reply. In my typical use I turn off audio input from the non-active (PTT) radio. I don't change volume or switch to unused freqs. There are few unused freqs in the CA bay area.

With my 2 button solution I would be able to have any combination of radio monitoring - not just one radio. And I think there's a way to wire the audio selectors with the PTT switch to prevent the active radio's audio from being switched off.

What I'm planning is two on/off buttons ([C1] and [C2]) for comm audio-in from the radios. The trick will be preventing the active radio from being turned off which, as you point out, would be a bad thing.

Also, most radios today have standby monitoring so having both radios' audio on can be pretty crazy on the ears if you are monitoring on both. Not a likely case but in busy airspace I'm sometimes listening to ATIS, ATC, and a nearby uncontrolled field as well. I like to be able to just hit a button to silence the extra freqs for a few seconds.

 

[BonitaRV8]

Neil,  Did this solution work?  I'm looking for something similar but I want to run the phones to a double pole three position toggle switch where left would be COM1, center would be both and right would be COM2.  The only concern I have is how to tie the ground shielding around the switch.

Thanks,

Scott