View Full Version : FRS or GMRS radios
12-27-2010, 07:59 AM
My boss, an active ham and several of his four wheel drive buddies are planning another trip out to AZ.
Several are hams, and several are not. FRS or GMRS radios? This would require the Hams to modify their UHF equipment to transmit on those frequencies.
They would like to rent hand held radios of which are similar, i.e. programming and batteries, etc.
This would make communications possible for all, including the non hams.
They would consider one mobile unit as a net control to be stationed in a high central location.
They would be only a few miles apart from one another.
I thought somone might be able to shed some light as to what and where, equipment is available.
12-27-2010, 07:21 PM
Legally, you'll have to stay away from GMRS unless everyone involved wants to fork over the $85 for GMRS licenses from the FCC. That constrains you to FRS and the shared FRS/GMRS channels; however, the radio power output on those channels is limited to whatever the radio puts out, which is usually 500mW. Over average terrain this probably gives you .25-.30 miles max usable range. With a high station in LOS to the lower stations, you can expect that to increase, but LOS to the high station from everyone else is a must. With a high station 500-1000' above surrounding terrain, you can expect a 500mW radio to jump up to a couple miles range. Forget renting...you can buy blister pack radios for dirt cheap, and most guys probably have enough of them sitting around in drawers you could outfit a small army.
Another little known band which has a little better potential with no licensing required is the MURS band. It's 5 channelized freq's just above the 2m portion of the amateur band (151-154 MHz). Max power out of a MURS radio is 2W and you can have an antenna that is separate from the radio, unlike FRS. I doubt you'll find equipment to rent, but you can probably look for a batch of commercial VHF high band radios on a popular online auction website and get a batch of them for fairly cheap. I'd recommend buying Kenwoods, as they don't have the programming software legal issues associated with Motorola radios. Search for Kenwood TK-2100 or similar radio. Software and a cable to program the radios can easily be found on the same online auction site. Best cable prices are probably at
An alternative solution would be (as much as it pains me to say it...no flames please) to look into 11m (Citizens Band) radios for everyone. CB's have up to 4W power out for AM ops, are plenteous and cheap, and I'll bet half the guys already have one in their Jeep. Hand-helds are not optimal with this setup, but if you're just looking for a trail radio, tossing an 11m radio in your rig is easy and cheap. You'll get a couple miles out of an 11m rig, and probably not even need a high station most of the time. (Unless you're in varsity level terrain.)
I will note that the cost to take the Technician exam is only $15, requires a minimal amount of study, and is the start of a hobby that can last a lifetime. The up-front amount required to outfit a new ham is easily recouped over the life of the hobby, and creates an enormous amount of diversity, flexibility, and power in operating capabilities. Whether it's APRS for 4x4 mobiles, repeater autopatches for those important phone calls you need to make when you passed the last cell tower 2 hours ago, or HF for the ultimate in off-road communications...it's never a bad thing to create more 4x4 Hams.
12-29-2010, 06:15 AM
While it isn't actually illegal to modify the HAM UHF radio to transmit on the FRS/GMRS frequency, it is illegal to actually transmit in those bands with a modified HAM radio. All radios used in the FRS/GMRS band are required to be type accepted for the band and a HAM radio is not type accepted. Same thing holds for MURS.
Best thing is to try and get everyone licensed but if that isn't a option I would have to agree with the CB route. I really haven't found much usable difference between a CB and FRS radio in most cases though. Neither works very far but CB does hold the advantage when you don't have S9 noise levels.
Now that we have given the legal argument. FRS/GMRS is where CB was in 75-77. The FCC isn't going to enforce the licensing requirement as there are too many people using these cheap FRS/GMRS radios without a license to make it enforceable. They are only requiring the license to try and get a little revenue from the honest people. As long as you aren't causing interference and such they won't even look to see if you are licensed.
12-29-2010, 02:39 PM
I concur with Leonard's assessment of the legal status of GMRS. In fact, the FCC is currently considering a rule-change to GMRS that would eliminate the licensing requirement, as well as allow the transmission of packet (think APRS) over one of the channels. I guess I'm OK with that, since they've given up on enforcing the band now. (A little bit of a sore spot, since I'm one of the guys that did actually bother to send them the $85 for a license.) At least under the new rule I can still use GMRS at no cost without the constant threat of the FCC bandwidth police showing up at my door one day to do a "station inspection" and putting my ham license at risk. Although the FCC probably doesn't care about blister pack GMRS users, I'm not so convinced you would go unnoticed if you were using a bunch of 50W UHF commercial mobiles. Those things have a little range, and certainly stand out compared to the barely communication-grade signals from blister pack radios. Not an issue if you're way out in the desert, but if you're high up and close to town, someone might take notice.
I would definitely shy away from modified ham equipment on either MURS or GMRS. Although your chances of getting caught are slim to none, in my opinion the risk isn't worth the reward. FCC fines can get expensive. Used commercial radios are much cheaper (and durable) in my opinion. Maybe someday FlexRadio guys will invent the all-band/all-freq SDR radio and I can have HF, CB, VHF, UHF, MURS, GMRS, and 900MHz all in one radio and get some space back in the cab of my truck. Probably a trade-off, since I'll lose a lot of exterior space to antennas. :)
12-30-2010, 08:04 AM
Thanks to the replies, I will forward this information to the interested parties.
12-30-2010, 05:14 PM
Maybe someday FlexRadio guys will invent the all-band/all-freq SDR radio and I can have HF, CB, VHF, UHF, MURS, GMRS, and 900MHz all in one radio and get some space back in the cab of my truck. Probably a trade-off, since I'll lose a lot of exterior space to antennas. :)
The problem isn't creating a radio that will do all the bands. My FT857 with the jumper mod will do most. (Don't think it does MURS and can't do 900). The problem is type acceptance. No ham radio will be type accepted for non ham bands and especially for the commercial type bands.
12-30-2010, 07:33 PM
What? You mean Federal Regulations are responsible for the mess of radios that's on my transmission tunnel? I thought the government was here to help?
12-30-2010, 07:58 PM
Nope, they are only here to collect license fees.
12-31-2010, 08:35 AM
Good, informative thread. I learned more about GMRS/FRS reading though this than I ever have on the other radio services.
I agree with the CB option. I use it on the trail all the time. I carry a couple of hand held CB rigs for those on our trip who don't have radios. It just makes it so much better when the rigs can communicate, point things out along the trail, comment on the scenery, etc.
You know, the ironic part of it all is trail use is exactly the kind of thing CB is intended for. Somehow it became an underground/knockoff ham radio service back in the 1960s and 70s, but that wasn't the original plan. The lack of enforcement coupled with the desire on the part of several manufacturers to sell radios kept the illegal use going. Fortunately, on the trail you usually don't hear all the garbage that occurs on the regular CB channels.
12-31-2010, 12:29 PM
I actually prefer using CB on the trail when in tight groups. No need to worry about ID'ing all the time or being Politically Correct. Not that I have ever been accused of that. :)
The OP stated: They would be only a few miles apart from one another.
In my experience neither CB of FRS / GMRS would suffice. A lot depends on the terrain.
A lot depends on terrain, but I rarely have issues with my CB getting up to 10 mile coverage. With a good CB and antenna, that's not a problem.
01-06-2011, 09:01 AM
A couple of things come to mind.
You might see improved FRS performance if you use your UHF ham radio - and antenna - to LISTEN, but use your FRS HT to transmit. That keeps you type accepted, but the use of the external antenna would greatly improve range, just like when you have a 2m HT in your truck and then hook it to an external antenna. Reception improves significantly, even if you can't change the other end.
If you already have a UHF ham radio in the rig, what do you have to lose?
Now, if you're beyond line of sight and on opposite sides of mountains, what you really need is 80m NVIS. :D
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