I’d like to be able to use a portable radio (such as the Yaesu 750L) in-flight at the same time as my airplane’s built-in radio / intercom. (Use cases: Air-to-air communications, or to listen to ATIS without having to ask AFIS for a temporary frequency change or changing from mountain frequency).
I guess just using a passive “Y” cable adapter to plug my headset into both radios won’t probably cut it, due to impedance issues?
Does anybody know a suitable solution for this (commercial or DIY)?
ps engineering is making a small audio panel PS4000
This one has 2 COM inputs (and 2 NAV) with what you need in order to switch from one radio to the other one.
I have one to sell that will come out of my panel end of April if you are interested.
Looks like an interesting piece of hardware, but at ~$850 probably a bit over my perceived budget for the (simple?) task.
It may not be impossible with a Y-adapter but it looks like a minefield. For just one example, both radio’s will offer the bias voltage for the microphone. And two power amplifiers driving the same load will go down heavily, too, at least some resistors would need to be added but they come with their problems. It might perhaps perhaps work between radio X and radio CBA321 but if you then swap X for FGJ641 things would go all wrong.
The right way to go about this is to use an intercom, to some also known as an “audio panel” ;) as rightly stated above. I must agree though that 850 quid is out of proportion.
But frankly, the one reason I carry a handheld Icom A6 in the emergency pack is that it is totally unconnected to the rest of the system – as soon as things are connected, one may pull the other down. As the folks at EBBR tower learned not very long ago: they suffered a total power outage and lost all radio comm’s, too, making them effectively deaf and mute. Better keep your handheld well apart from the rest of your avionics.
Jan_Olieslagers wrote:
But frankly, the one reason I carry a handheld Icom A6 in the emergency pack is that it is totally unconnected to the rest of the system – as soon as things are connected, one may pull the other down. As the folks at EBBR tower learned not very long ago: they suffered a total power outage and lost all radio comm’s, too, making them effectively deaf and mute. Better keep your handheld well apart from the rest of your avionics.
Is this really a concern in VFR flying outside of controlled airspace? I’d reckon that you’ll know quite quickly if your radio doesn’t work. In any case, you can fix it by unplugging the handheld.
It certainly wouldn’t be for 100% use (then I’d want a second fixed radio, if I had the panel space), but for the occasions that a second radio connection for a few minutes would be useful.
