Wireless speaker mic for 2-way mobile radio using FRS

[WSHE710]

I was wondering if anyone makes wireless speaker/mic that Utilizes a 2-watt FRS channel?  The idea being you could hook it up to your mobile radio in your car. Take this microphone a good 100 yards away from your mobile to do something on foot but still utilize the 50-Watt transmitter in your car instead of a 5-watt HT. 

If there is not already one commercially available, I thought that it might be possible to take a couple FRS radios with VOX in them. Cannibalize one of them to make a receive and transmit unit and hook it up through the microphone port on your mobile radio. All the pin-outs would have to be figured out but I think it could be done. Has anyone ever tried building one of these and if so, how did it work out?

[Jaay]

3 hours ago, WSHE710 said:

I was wondering if anyone makes wireless speaker/mic that Utilizes a 2-watt FRS channel?  The idea being you could hook it up to your mobile radio in your car. Take this microphone a good 100 yards away from your mobile to do something on foot but still utilize the 50-Watt transmitter in your car instead of a 5-watt HT. 

If there is not already one commercially available, I thought that it might be possible to take a couple FRS radios with VOX in them. Cannibalize one of them to make a receive and transmit unit and hook it up through the microphone port on your mobile radio. All the pin-outs would have to be figured out but I think it could be done. Has anyone ever tried building one of these and if so, how did it work out?

There Are several Wireless speaker mics on the market, but most of them only have a limited range of about 35-50' being that they're blue tooth. What you're probably referring to is something like a Simplex repeater, or a Mobile Extender.  Or a talkie set to low power, a half watt or so, and and a Dual band mobile with Crossband Repeat would do what you want.

[SteveShannon]

5 hours ago, WSHE710 said:

I was wondering if anyone makes wireless speaker/mic that Utilizes a 2-watt FRS channel?  The idea being you could hook it up to your mobile radio in your car. Take this microphone a good 100 yards away from your mobile to do something on foot but still utilize the 50-Watt transmitter in your car instead of a 5-watt HT. 

If there is not already one commercially available, I thought that it might be possible to take a couple FRS radios with VOX in them. Cannibalize one of them to make a receive and transmit unit and hook it up through the microphone port on your mobile radio. All the pin-outs would have to be figured out but I think it could be done. Has anyone ever tried building one of these and if so, how did it work out?

I don’t think that what you’re proposing would be compliant with the regulations.  You’re trying to make a repeater that receives from a FRS radio and simultaneously transmits as a GMRS transmitter despite the official repeater input channels being excluded from the FRS frequencies. The easiest way to do that within regulations would be to simply place a GMRS repeater in your car and use a GMRS handheld when on foot.

 

[WSHE710]

Thanks for all the feedback guys I appreciate it. The original question was, has it been done or whether or not is it Mechanically feasible to do it this way. I had not actually considered the legality end of it, just the mechanics. Well, I did go ahead and double check on the FCC rules and you guys are right, not Legal according to FCC rules.  It is a shame that there’s not something like a Super Bluetooth which could get that kind of range. I do know that Motorola makes a wireless microphone for one of their radios that does have, I believe up to a 100 yards range. I don’t know what frequency they’re using or how they’re doing it. it may be some kind of digital thing for all I know. Oh well another brilliant idea flushed down the toilet. LOL Thanks Again for the feedback.

[SteveShannon]

4 hours ago, WSHE710 said:

Thanks for all the feedback guys I appreciate it. The original question was, has it been done or whether or not is it Mechanically feasible to do it this way. I had not actually considered the legality end of it, just the mechanics. Well, I did go ahead and double check on the FCC rules and you guys are right, not Legal according to FCC rules.  It is a shame that there’s not something like a Super Bluetooth which could get that kind of range. I do know that Motorola makes a wireless microphone for one of their radios that does have, I believe up to a 100 yards range. I don’t know what frequency they’re using or how they’re doing it. it may be some kind of digital thing for all I know. Oh well another brilliant idea flushed down the toilet. LOL Thanks Again for the feedback.

Why not just do a mobile repeater. It accomplishes exactly the same thing in a less complicated way and without regulation issues. 
I haven’t heard of anyone doing what you described and I think desense would be a killer. 

[WSHE710]

21 hours ago, SteveShannon said:

Why not just do a mobile repeater. It accomplishes exactly the same thing in a less complicated way and without regulation issues. 
I haven’t heard of anyone doing what you described and I think desense would be a killer. 

Steve

I was thinking the very same thing, in fact yesterday I ordered a Retevis M1, 50-Watt Mobile. It’ll do cross band repeat which should work out just perfect for me. I have a VHF frequency that I can use and It is a UHF frequency which I want to use for the 50 watt transmissions. I did try this once before on an Icom 2730 and I ran into a problem. When using it as a repeater it would not transmit the PL code, I had assigned to it. I checked several reviews of the M1 radio and a couple of them mentioned Retevis did do an upgrade to get it to transmit the PL code.

Thank you all for your input.

[WSHE710]

I connected the Retevis MA1 50-Watt Mobile to my car, did the proper programming and it's working really well. There is a slight delay on transmit so when pressing the button I need to give a short pause before speaking. I have not as yet been able to get far enough away from the car that it does not continue to operate the mobile repeater.  I have it connected to my auxiliary battery not my main cranking battery, so it Will stay working even when the car is shut off. It is a sealed lead acid 20-amp hour battery So I should get at least a couple of hours out of it, depending upon usage before the battery gets too low.

[WSEH477]

Question concerning the Retavis Ma1 as the specs states the transmit frequrncy range doesnt cover GMRS. Is that range extendable?

[SteveShannon]

37 minutes ago, WSEH477 said:

Question concerning the Retavis Ma1 as the specs states the transmit frequrncy range doesnt cover GMRS. Is that range extendable?

It looks like this only involves amateur frequencies. 

[PACNWComms]

On 11/8/2025 at 12:32 PM, WSHE710 said:

I do know that Motorola makes a wireless microphone for one of their radios that does have, I believe up to a 100 yards range.

I use Motorola Bluetooth Remote Speaker Mics (RSM) with Motorola mobile radios, where a zone has been set for GMRS use. Often in clear open areas, my RSM gets that kind of range. I also use one for my daily job, with a 7/800 MHz APX4000 being the radio it connects to. 

Recently, Motorola has been fumbling their model numbers, firmware, and what will work with which product lines. Some Bluetooth RSM's from Motorola used to work with both APX and XPR Trbo series radios, but now they are differentiated a little more, by model and firmware. Beware, many sales sites have not updated this. 

(For example, my PMMN4095A Bluetooth RSM works with Motorola APX series radio, but not Trbo). Be careful if you go down this path.....but, it is not a repeater, only a wireless microphone going to your radio, so no legal issues. They are also on a Motorola proprietary wireless setting (unless you disable that and set it for a more common standard, which does reduce range but allows for non-Motorola wireless devices (small remote PTT, hearing aid use, that type of thing). 

[gortex2]

They make 2 BT speaker mics now (well technically 3 SVX). The new BT speaker mic for the Next is even better than the old unit. The new one I like the pairing is done once and never touch it where as the WM SM you had to touch blue dots every time you turn the radio on. The new SVX (w/built in body cam) also pairs once and done. As said I can get 100 yards on mine. I have been in a house and still connected to my vehicle in a driveway. 

 

[PACNWComms]

17 hours ago, gortex2 said:

The new one I like the pairing is done once and never touch it where as the WM SM you had to touch blue dots every time you turn the radio on.

I am still in the "pair the blue dot every time" version myself.....forces me through a routine each morning. But, a co-worker has been playing around with the the new versions as well. Seems to go over well with the end users. Not sure how the camera is going to work out, many were worried when laptop computers had cameras by default too though. time will tell. 

(I actually had to place painters tape over some Motorola 6-bank chargers, as they had the second set of cups for the RSM's with cameras, some sites bought those while others did not, but all the 6-bank chargers were the same). Had to manage expectations for a short time, until budget caught up (private fire departments, we do not get grant money). 

The original end users of wireless remote speaker mics was forklift drivers, that had a problem with running over their radio after hooking up a towed load. Radio went on the forklift fender, was left and often run over by the towered load or the forklift itself. Replacing that wireless RSM was much cheaper than a radio. My use case came from me mentioning that I often broke wired remote speaker mics in armored military vehicle doors.....doors that would slide the coiled cord instantly. Do that a few times and a Bluetooth option looks cheap. Need to try on of the newer ones, once I get my hands on one. 

[WRUE951]

I've got a Hytera BT Mic for one of my commercial Mobiles and it works quite nice