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Panel switch for two comms if no audio panel?

RickWoodall

Well Known Member
I have a mgl v10 comm that is intercom and radio, been good for a decade.
Decided to upgrade to a Garmin GTR200B that is the same in that it is radio, plus intercom so one stand alone unit, no separate audio panel.

Basic vfr bird.

Question for those that know products out there...

If i dont want to spend $1000 plus on an audio panel, but i would like to leave both stand alone radio/intercom units in plane is there a box i can buy that would allow me to wire both in and pick one or the other?

I will use the Garmin 100 percent of the time as it has blue tooth etc, but if it ever let me down, flipping a switch and sending juice to the MGL as my back up would be perfect instead of reaching for a handheld. Ideally a box that allowed antennae and power etc from two radios to go in, and me flip a switch to power comm one or two would be ideal without a fancy $1200 box, second antennae etc. Anyone know of a solution?
 
You are describing something that an audio panel doesn't do. It would allow you to switch between radios for output (headset) and input (mic/PTT). I've got a recent thread about a DIY audio panel that has some great simple suggestions to do this (not so much my starting idea, but some of the responses). Look for my thread in the COMM sub forum from a couple of days ago.

The audio panel (or the DIY alternative) won't handle the switching of power between the 2 radios or allow for the sharing of an antenna. The power would be simple enough with a SPDT On-On switch. No idea if you could use the same antenna though.

I guess if you are switching power, you could just splice the audio lines together as you'd only have one radio at all times.
 
Pretty easy to use a simple switch (3PDT / On-On) to move your headest/PTT feeds between two comms. No simple approach to switch the antenna though. However, you could run the three coax feeds to BNCs (male for each comm and female for the antenna feed) near the pilot somewhere to switch the antenna in the event of a failure. Definately better than going to the handheld.

If you wanted to maintain intercom function when going to the backup comm, you would need a switch for each headset. I suspect this is emergency only and intercom is less important. Certainly wouldn't have it with a handheld.

Larry
 
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Never connect two radios to a single antenna, and do not attempt to use a standard switch for an antenna. If you really must have an antenna switch, it has to be a switch designed for coax, such as: https://www.dxengineering.com/searc...h&sortby=BestKeywordMatch&sortorder=Ascending

Note - most of these use PL-259 UHF connectors instead of BNC.

But - if the objective is to have a second stand alone radio, having common coax and single antenna violates this objective. Just add a second comm antenna. It need not be an anything fancy or expensive, and you can put it in a wingtip if you don?t want it out in the breeze. A wingtip comm antenna will not work as well as a belly antenna, but for a backup it will be more than enough. I have a lot of hours flying with a single home brew wingtip comm antenna so have some experience in how they work.

Carl
 
Second ant.

I dont have any issue running a second ant, if that is a no no to use a splitter.
I was trying to muddle through this planning and layout and see that i think my new Garmin GTR200B can do the the trick if i run my mgl v10 into it as a audio input...with a switch. Uggh.

Cants say this part comes easy to me. Thanks for tips. Much appreciated.
 
I was trying to muddle through this planning and layout and see that i think my new Garmin GTR200B can do the the trick if i run my mgl v10 into it as a audio input...with a switch. Uggh.

That won't help if your primary objective is to only use the V10 if the Garmin fails.

Larry
 
I set up my VFR RV-4 20+ years ago using two small SPDT switches. One for X-Mit which routes the transmit button signal to one radio or the other, and RCV, which routes the radio audio outputs to a sigtronics ICS. The only reason I used two switches is I couldn't find one switch I was happy with, and I had the two already on hand.

I have two antennas, but that might be a separate issue in that an audio panel would still requires two antennas (I think).

The downside of this system is it's not a true two radio set up, as you can't monitor both radios at the same time. Perhaps there is an easy fix to this someone can suggest.
 
yup

But any audio panel/mixer with multiple comms would be a single point of failure no? Uggh
Maybe i will just fly in the sticks and use light signals. :-(
 
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