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2 radios, 1mic?

This forum is dedicated to helping people with questions about installing radio equipment in vehicles. This can include antenna installs, electrical wiring questions/problems, and mounting systems. Pictures of installs are welcome.

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2 radios, 1mic?

Postby LFD57 » Sun Mar 22, 2015 8:59 am

Hello everyone. Not sure if anyone has ever done this before but here we go.

I currently have single head UHF XTL5K, and a single head VHF XTL5K. My question is, is there a way to build a switch box of sorts to run only a single mic for both radios. I primarily only use the UHF but would like the emergent ability to use the VHF without having to install a second mic and mount it.

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Re: 2 radios, 1mic?

Postby Bill_G » Sun Mar 22, 2015 12:49 pm

Where would you get the connectors from? That's the hard part.

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Re: 2 radios, 1mic?

Postby LFD57 » Sun Mar 22, 2015 3:13 pm

Thouht of that too. It's an O5 setup so I think pretty easy, already have a mic extension cable that I could canabalize that.

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Re: 2 radios, 1mic?

Postby Jim202 » Sun Mar 22, 2015 3:56 pm

I think you could use the accessory connector on the back of the radios if they are low or mid power. If they are high power, use the DB-25 connector. You will have to change the setting in the software if it's a high power to get the external mic audio to work. Then make a switch box to flip from one radio selection to the other.

There is an external mic gain that is set in the radio software. Just make sure you don't get the gain up high as it will bring up all the background noise and cause problems with your mic audio if you get it too high. Use a hand mic from a Spectra and cut off the control head connector from it. Wire the mic into your switch box. You only need to switch the PTT and the mic high line to each radio.

These software settings in the radio do not effect the normal mic operation from the control head.


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Re: 2 radios, 1mic?

Postby Will » Mon Mar 23, 2015 9:49 am

Spectra mic cords will not solder well, they are the tinsel type.

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Re: 2 radios, 1mic?

Postby chartofmaryland » Fri Jul 24, 2015 3:51 am

Jim202 has it best,

The bricks DB26 on the XTL's work fine as microphone inputs.

Used an 8 pole dual throw switch to a radius microphone and all was well. Just parrallel the wiring to match function and your set.

Program the XTL to disregard HUB or if you require the mic ground you will always be in monitor on your analog resources. Scan will never work right again :( either.
If the lights are out when you leave the station and then come on the second you key up, you know you have enough power.

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Re: 2 radios, 1mic?

Postby Dispatch229 » Thu Mar 30, 2017 2:34 pm

Bringing up a bit of an old topic here, but I think its more appropriate than starting a new thread.

Can I get away with using a standard DPDT switch and only switching PTT and MIC HI (sharing GND and MIC LO)?

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Re: 2 radios, 1mic?

Postby motorola_otaku » Tue May 02, 2017 8:36 am

Probably best not to bridge those leads between radios, as it could create ground loop/voltage difference issues.

Isn't mic audio also available on the DB26 connection on the remote head too?
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