GMRS (General Mobile Radio Service) Anyone?

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Doc Roads

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Anyone use this service?  I was scanning with my UHF/VHF HT and caught a signal at 462.550 MHz.  It was two operators testing out their channel 15 GMRS repeater. I had no idea there was a repeater in the area.  I listened and learned a bit about GMRS ... researched it on the internet and found out quite a bit about it.  This set of frequencies is reserved for personal use and the license you must get from the FCC covers the whole family.  I?ve had a hard time getting DW to get interested in passing the Ham Tech license but she has no problem using an FRS handheld but that has a very limited range .... so this may be an alternative for connectivity between vehicles, fishing trips, and longer distances without the CB color and chatter ... FRS and GMRS freqs overlap ... FRS is a couple watts and GMRS allows up to 50 watts on select freqs. Seems pretty capable and flexible ... anyone have anything to add?
 

Gary RV_Wizard

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Many "walky-talky" type radios cover the channels in the GMRS spectrum, and few owners bother to get a license for them.  My Motorola Talkabouts are an example, but they are relatively low wattage (2W on GMRS?).  In practice, as long as they are only used for personal (family) communications and you aren't pumping out the max allowed 50 watts, I doubt if anybody would ever ask about having a license.
 

Larry N.

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Gary's probably right, but I would suggest that if you get radios other than the combo handhelds (FRS/GMRS) that you get the license. Those fines can be pretty steep sometimes, and the hassle alone would be less than pleasant.
 

Lou Schneider

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A GMRS repeater uses different frequencies to receive and transmit.  You need a radio that can do the same to use the repeater.

Inexpensive FRS radios can operate simplex on the same frequencies, so they can hear the repeater's output.  But they can't transmit into the repeater unless they're capable of split frequency operation.
 

HappyWanderer

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Lou Schneider said:
A GMRS repeater uses different frequencies to receive and transmit.  You need a radio that can do the same to use the repeater.

Inexpensive FRS radios can operate simplex on the same frequencies, so they can hear the repeater's output.  But they can't transmit into the repeater unless they're capable of split frequency operation.

An unlicensed operator could unknowingly cause interference by using simplex on the repeater input frequency. They would never hear the repeater and would be completely unaware of the interference.
 

Doc Roads

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Lou Schneider said:
A GMRS repeater uses different frequencies to receive and transmit.  You need a radio that can do the same to use the repeater.

Inexpensive FRS radios can operate simplex on the same frequencies, so they can hear the repeater's output.  But they can't transmit into the repeater unless they're capable of split frequency operation.
Yes, in 2017, FRS use was approved for the GMRS channels but FRS transmitters are limited to not more than 2 watts or less ... FRS certified radios are not capable of using the repeater offset too and no license required.  BTW, make sure the GRMS radio you select can handle offsets, some don’t. I want to be able to talk short and long range via the repeater.  That’s the plus I see ... clear FM signal, repeater capability for good range, up to 50 watts transmitter power for more simplex range, no test for the DW to take, and at a reasonable price for me.  Jeep off-road clubs are moving from CB to GMRS for most of the same reasons.  CB is AM and inherently has more static ...

I plan to install a 15 watt mobile station in my MH.  Just working on the installation to be compatible with all the other “stuff” I have on top and in the overhead compartments.  I nominate channel 15 as the RV channel to monitor ... maybe there’s already one nominated!
 

Doc Roads

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Here?s a quick comparison ...
What are some of the pros of GMRS over CB...
Power: CB is limited to 4 watts (AM) or 12 watts (SSB which most don't use offroad). GMRS can have up to 50 watts.
Modulation: CB is AM (typically used offroad, some CBs also have SSB, Single Side Band). GMRS is FM. Just like in your vehicle, FM has better audio quality. AM is more susceptible to environmental RFI (Radio Frequency Interference)
Repeaters: CB doesn't have repeaters. GMRS is repeater capable to increase range, though typically only around metropolitan areas.
Antenna: For CB the optimum mobile antenna is 108" (1/4 wave), anything shorter is a compromise. For GMRS a 1/4 wave antenna is 6" and needs far less ground plane than a CB antenna so it can be mounted virtually anywhere.

This is an extract from a Jeep Forum ...
 

Larry N.

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What Doc says about the comparison is correct, but I'd mention that the AM of CB at short ranges is pretty much as clear sounding as the FM of FMRS, business bands, etc., but with weaker signals the interference can certainly be a problem. As to antenna length, the 108" is correct for CB, as far as it goes, but that's electrical length. Most CB antennas these days (and even in the '60s in its heyday) use various loading coils to get an effective 108" electrically while having physical dimensions no more than a couple of feet, in many cases, for use in magnetic mounts, trunk lip mounts, etc. Still, GMRS is a good way to go if you don't need the potential contact with a broad range of folks (especially truckers) in case of emergency/whatever. And even without repeaters, the range for GMRS should be longer than that for CB in most cases (not all -- radio waves act funny at CB freqs, not talking about skip).

So for your stated purpose the GMRS is probably best. Of course you could do both. ::)

 

95f5334j

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I nominate channel 15 as the RV channel to monitor ... maybe there?s already one nominated!

I'll start listening to channel 15 while driving, I had already programmed several GMRS frequencies into my 2m/70cm radio in the coach and my HT to use with my GMRS radios when we're at campsites / state parks etc.
 

Doc Roads

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I use my HT to scan and monitor UHF/VHF too plus GRMS freqs.  Ch 15 is what I monitor too ... it?s a common repeater frequency and is used often in my Southern Arizona area.  So Ch 15 is being monitored by at least two RV Forum members!  I suppose that makes it almost official!

 

Gone2dMtns

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I just recently received my GMRS license and decided to pop over here to see if anyone in the RV community was using the medium. Yes the thread is over 4 years old and it's refreshing to see that some of you have adopted the medium early on. I honestly didn't know anything about GMRS until about a month ago I was looking to dust off the CB and started watching some YouTube videos when some GMRS videos started popping up in the list. The more I watched the more I was interested in pursuing this flavor of two way radio communications. I chose a multi-band radio to additionally have the ability to get NOAA broadcasts, listen to local fire and police dispatch, and VHF Marine chatter. There are a couple of RV campgrounds near the house so I may drop by to see if I can engage anyone in participation but for now the airwaves a pretty dead. Perhaps in the future I'll setup a repeater since I am in the sticks.
 

Rob&Deryl

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Back in the mid 90s I built a 25 watt (I think) repeater at 462.550 for portable use by volunteer groups. It is in a 4u road case with an interesting jpole design antenna. We used it with Icom U16s at World science fiction conventions. We put it and it’s antenna up high in convention centers. Anyone want it?
 

John From Detroit

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GMRS is a rather useful radio. more power, range and channel options than FRS but you do need a license (80 bucks for 10 years) I had one for a while but gave away the radios after my wife died.

I prefer my Ham license. it's only 35 for 10 years (that starts next year just now it's free) and I can not only do a few watts on 462.55 or there abouts but 1000 watts on a wide range of frequencies from just above AM broadcast to visible light.
 

Gone2dMtns

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GMRS is a rather useful radio. more power, range and channel options than FRS but you do need a license (80 bucks for 10 years)
The FCC announced month's ago that the GMRS license fee will be $35 for a ten year period however it has yet to be reflected through their ordering system. The current rate is $70 for a ten year period. Rumor has it that it will not be until after the new year into 2022 before the cost reduction. I believe HAM licensing is affected also but I don't know the details of that.
 

Jkoht

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I started using FRS radios to keep in touch with hunting partners over 10 years ago, and gradually we shifted in GMRS handheld once they became available and offered better range. We have slightly phased them out now as cell phone signal has improved over the years. We still keep some at the cabin for people out fishing to check in quickly, and I carry a pair in my truck for my wife to assist when I'm backing the camper into a site. I've never bought the license, which I know is required, but we never use them for long periods of time and so far have never been bothered by any FCC agent. We also used them at times when traveling with a group of vehicles just to alert people to pit stops or bathroom breaks. Turn one on in a major city and set it to scan and you often find parking lot attendants and low grade security guards using them.
 

Gone2dMtns

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Given the licensing requirements for HAM operator license now vs GRMS requirements, why not go ahead and study for a HAM license?

There are no requirements to obtain a GMRS license other than paying the fee. That's it. No studying. No tests. No having to track down a HAM club to take a test or dealing with a bunch of arrogance that we all know exists. Once the GMRS application has been approved and call sign given out then the members within the licensee's household can also participate under the same license and call sign. You can't do that with HAM. We can freely chat with our family (kids too) and if we're out hunting or fishing with our buddies and they aren't licensed, then no problem. Just throw them an FRS radio and they can chat with you on some of the GMRS channels. No complications!!! And the best part is the equipment is very inexpensive. Of course, as with any other hobby, you can invest as much money as you wish into it. So there's your answer. Honestly the only thing the GMRS license does for you is allow you to talk on a radio with higher wattage and be able to use repeaters. I believe that GMRS fits a niche for those of us that don't want the complications of HAM.
 
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