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Posted

Hey all, I obtained a GMRS license so that my entire family can operate without everyone having to be independently licensed while out of town camping and four-wheeling where there's no cell service.  I've had an amateur radio technician license for over 20 years but only operated from time to time, and frankly never for much more than talking to licensed friends on 2m on outings much the way GMRS is used these days.  It seemed to follow that going GMRS with the family license and where friends could obtain inexpensive licenses without tests would make the most sense for casual use.

To be honest once we tried operating I wasn't particularly impressed.  I bought a pair of Tidradio TD-H5 radios (chosen because they were advertised as 5W and came with handmics) and I also bought a pair of mag-mount antennas that claimed 400-470MHz operation.  We did some testing and found that the limit on range was shorter than expected, around 3200' in a suburban area generally lacking tall foliage, and was actually worse with the mag-mount antennas, working to only around 2000'.  I had even tried working on the connectors on the antennas, the SMA connector on the factory rubber-ducky has a very long pin and looked like the internal barrel interfaced to the barrel on the radio more effectively than the mag-mounts, but even taking the connectors apart and trimming a little to make the pin-stickout and fitment better didn't help.  The range with the rubber-ducky antennas was disappointing since I had experience talking several miles on 2m with 5W on simplex, and even had an experience talking the better part of 40 miles with a mag-mount on the roof of a cargo van once.  I had expected to get a few miles even with the higher frequency being less useful for distance.

And before anyone asks, I don't have an SWR meter.  Digging through all my old radio/ham gear I have a watt-meter and a dummy load but I don't yet have the right connectors or plug-in modules for the sorts of power levels that a GMRS HT will transmit at.  Will need to obtain some stuff.  Back when I was operating ham almost everything was BNC or UHF connectors, and the switch to SMA was a bit of a surprise.

The mag-mounts I had bought are admittedly predominately for VHF/UHF ham radio 2m and 70cm, which could explain why they made things worse and that the manufacturer was simply full of it when listing them.  Anyone have suggestions for GRMS-tuned mag-mounts or NMO-mounts that perform well and are reasonably priced?  I'd like to avoid further spending money on equipment that works worse than what came with the radios.

 

Posted

For GMRS, I have been pleased with my Nagoya UT-72G (mag mount), and Midland MXTA25 (NMO mount) when I wanted to save some height to stop running into my garage door.  The Midland MXTA26 (NMO mount) seems to get terrific reviews for GMRS also, that may be my next GMRS antenna.

Posted
1 minute ago, back4more70 said:

For GMRS, I have been pleased with my Nagoya UT-72G (mag mount), and Midland MXTA25 (NMO mount) when I wanted to save some height to stop running into my garage door.  The Midland MXTA26 (NMO mount) seems to get terrific reviews for GMRS also, that may be my next GMRS antenna.

I'll have to look out for those models.

In theory I have an NMO-mag-mount around here somewhere, magnetizes to the roof and has NMO for whatever antenna I would choose.  But I can't find either it or my longer 2m/70cm high-gain rubber-ducky.  I guess this is what happens when you don't operate for nearly a decade and lose track of where you've put stuff.

If I can make GMRS work better than it did this last test then I might buy some mobiles for the truck, travel trailer, and my wife's Jeep, and have the handhelds available for hiking or otherwise when the group separates from the vehicles.  But I want to prove it out for my application before I commit to spending hundreds of dollars.

Posted

Also for my GMRS HTs I sometimes use a Nagoya NA-771G, or a Nagoya NA-701G when I get tired of poking myself in the eye.  These both are optimized for GMRS, like the previous antennas I mentioned.

Notarubicon has good videos on YouTube if you want to get ideas without breaking the bank, but @OffRoaderX will tell you that you are his favorite viewer.  Don't fall for it ?

Posted
1 hour ago, back4more70 said:

Also for my GMRS HTs I sometimes use a Nagoya NA-771G, or a Nagoya NA-701G when I get tired of poking myself in the eye.  These both are optimized for GMRS, like the previous antennas I mentioned.

Notarubicon has good videos on YouTube if you want to get ideas without breaking the bank, but @OffRoaderX will tell you that you are his favorite viewer.  Don't fall for it ?

I am familiar with the channel.  Your assertion makes one speculate on the opinions of those that aren't his favorite viewer.

Posted
1 hour ago, WRXN668 said:

around 3200' in a suburban area generally lacking tall foliage

That's about right in flat single-two story suburban area for a decent handheld. But outside of the town when camping and four-wheeling, it will be different. Both much better and worse, depending on the terrain. If you have line of sight, your Tidradio HTs will talk to each other at 40 miles distance. In my experience, 2m is better in forest and rolling hills, and GMRS/70cm is better in rocky canyons. That is if we are talking about handhelds. You can install mobile radio with more efficient antenna, better receiver and more power, increasing outdoor range somewhat, but still remember about line of sight. No LOS, all bets are off. There is also much less RF interference outside of the town, improving the reception.

Posted

GMRS will work about as well as the 440 ham band. A NMO Mag mount with 1/4 wave UHF antenna is one of the better antenna's you can use. Any commercial LMR 1/4 wave will work fine. You range sounds about what I see during caravans on Jeep events or travel with family. To be honest MURS may of been a better option and no license, but no repeaters. 

 

Posted
29 minutes ago, gortex2 said:

GMRS will work about as well as the 440 ham band. A NMO Mag mount with 1/4 wave UHF antenna is one of the better antenna's you can use. Any commercial LMR 1/4 wave will work fine. You range sounds about what I see during caravans on Jeep events or travel with family. To be honest MURS may of been a better option and no license, but no repeaters. 

 

I look at the power levels for MURS being a bigger issue.  One can crank-up the power on GMRS but MURS is limited to 2W and from what I've seen, it looks like it's fairly distance-limited on account of that.

Still might acquire some MURS radios in the future, especially if the costs are low, but that would be hand-a-radio-to-unlicensed-friends sorts of scenario.

Posted

Just as Amateur Radlo Licensees, I started on the 11m band aka CB radio. I took my exam on 06 February 2003 and granted KB3JCP 11 February 2003. June 2004 is when applied for GMRS license and there's times that I don't really use it, but I do make use of both at the City to Shore MS 150 for nearly 20 years.  Once I upgraded back in 2014 I applied for a vanity license K3JCP.

I really can't get my father to use a cell phone and never really tried to get him to use GMRS. I wish I could get pick the radio, because I have access to 2 repeaters that if need him or he needed me, we could have connection.

 

 

Posted

I have zero experience with Tidradio, but 0.5 to 0.8 miles in the suburbs sounds pretty normal and my exact experience in most places I visit. In a flat area with zero obstructions, your range is going to max out around 3.5 miles.  I think the fact that we can use repeaters makes the service desirable for many people, since range gets extended anywhere from 8 miles for a causal home setup to 100+ miles for a mountain top repeater.

 

As far as handheld radios go, I am a huge fan of Wouxun.  I would recommend either the KG-905G or the KG-S88G.

 

Larson, Comet, Diamond, Laird and several others make great 3.5" to 5" mag mounts.  Any major brand should be fine.

 

My favorite 2 antennas for GMRS are the Midland MXTA26 gain antenna for flat areas and the Tram 1126-B for hilly / mountainous areas.

 

If you don't find your SWR meter, the Surecom SW-102 is surprisingly accurate.

Posted
3 hours ago, WRXE944 said:

If you want to interleave unlicensed "friends" to add to your GMRS family of communicators, FRS would be the better unlicensed option, since it is frequency compatible with your GMRS radios and still 2 watts when it counts.

Good point, I don't really know why I hadn't thought of that.

4 minutes ago, Adamdaj said:

Just as Amateur Radlo Licensees, I started on the 11m band aka CB radio. I took my exam on 06 February 2003 and granted KB3JCP 11 February 2003. June 2004 is when applied for GMRS license and there's times that I don't really use it, but I do make use of both at the City to Shore MS 150 for nearly 20 years.  Once I upgraded back in 2014 I applied for a vanity license K3JCP.

I really can't get my father to use a cell phone and never really tried to get him to use GMRS. I wish I could get pick the radio, because I have access to 2 repeaters that if need him or he needed me, we could have connection.

We had some kids' unlicensed walkie-talkies when I was a child, Dad had a weird oversized handheld CB that was sort of shaped like a telephone handset that he would listen to on road trips to hear if the truckers were talking about any traffic issues.  Beyond that we didn't really use communications radios much.  There would have been plenty of times when they would have been convenient, but never really thought about it.

 

 

Posted
15 hours ago, WRXN668 said:

Good point, I don't really know why I hadn't thought of that.

We had some kids' unlicensed walkie-talkies when I was a child, Dad had a weird oversized handheld CB that was sort of shaped like a telephone handset that he would listen to on road trips to hear if the truckers were talking about any traffic issues.  Beyond that we didn't really use communications radios much.  There would have been plenty of times when they would have been convenient, but never really thought about it.

 

 

Yep, those days are long gone. Those old 11m Walkie talkies had a larger footprint then the 49mhz radios that Fisher Price or Ty Co Electronics put out. Beside the squelch circuit in most of those transceivers didn't work. You always heard the static when no one was talking.  I had several of those CB handhelds of the years and always picked RF noise from Over Head Catenary near the PRR Northeast Corridor at Holmesburg Junction. Yep, my friend Jimmy and I would hang out at Holmesburg Junction and stay in tough with the CB. Jimmy would go to one end of Holmes Interlocking and I would hang out at the Tower.

Posted
5 hours ago, WRXE944 said:

Also, I believe they are the only HT option for DMR (on 2 meters and 70 cms) that also have capability for GMRS and MURS (analog, of course).

My D878 doesn’t have a problem with it either.

Myself I’ve been looking for a couple of radios that can do dPMR, which is used mainly in the EU. I haven’t seen it in North America so far. It’s very similar to NXDN but the protocol is different.

Anyway at least you didn’t get stuck with one of those crapy old Baofeng DMR radios.

Posted
5 minutes ago, wrci350 said:

What MARS/CAP mod?  It's a Part 90 radio so it will cover 2m/70cm as well as MURS and GMRS.  Not type-accepted on MURS or GMRS, of course.

There was some ambiguity when I inquired over on qrz about programming Part-90 devices for amateur radio bands, at least one response thought that it was an issue.  I'm pretty sure that Part 97 rules allow it though, expressly because part of the purpose of the amateur bands is experimentation/hobbyist pursuits, not just talking on off-the-shelf radios...

Posted
18 minutes ago, WRXN668 said:

There was some ambiguity when I inquired over on qrz about programming Part-90 devices for amateur radio bands

There is no ambiguity.  Part 97 does not require type acceptance so using a Part 90 radio is perfectly fine, and there are many hams who use older Motorola or Harris commercial radios.

One needs to be aware of a couple things when using a Part 90 radio:

1) As @Sshannon shows above, many Part 90 radios will do 136-174 and 400-480 MHz.  Obviously most of that range is NOT amateur radio (or even MURS or GMRS) so you need to make certain you are only transmitting where you are authorized to do so.

2) Unlike amateur radio, the FCC regulations for MURS and GMRS *do* require radios to have type acceptance, and a Part 90 radio like these does not have that type acceptance and as such is not authorized for use on those services.

Posted
4 minutes ago, wrci350 said:

There is no ambiguity.  Part 97 does not require type acceptance so using a Part 90 radio is perfectly fine, and there are many hams who use older Motorola or Harris commercial radios.

One needs to be aware of a couple things when using a Part 90 radio:

1) As @Sshannon shows above, many Part 90 radios will do 136-174 and 400-480 MHz.  Obviously most of that range is NOT amateur radio (or even MURS or GMRS) so you need to make certain you are only transmitting where you are authorized to do so.

2) Unlike amateur radio, the FCC regulations for MURS and GMRS *do* require radios to have type acceptance, and a Part 90 radio like these does not have that type acceptance and as such is not authorized for use on those services.

That's what I thought.  I'm not sure why someone was concerned about programming for amateur radio this way.

Posted
4 minutes ago, WRXN668 said:

That's what I thought.  I'm not sure why someone was concerned about programming for amateur radio this way.

It’s something that people are easily confused about. A type 90 accepted radio may be used on the amateur frequencies, but a radio built and sold for the amateur bands is not necessarily type 90 accepted. 

Posted
6 hours ago, Adamdaj said:

Yep, those days are long gone. Those old 11m Walkie talkies had a larger footprint then the 49mhz radios that Fisher Price or Ty Co Electronics put out. Beside the squelch circuit in most of those transceivers didn't work. You always heard the static when no one was talking.  I had several of those CB handhelds of the years and always picked RF noise from Over Head Catenary near the PRR Northeast Corridor at Holmesburg Junction. Yep, my friend Jimmy and I would hang out at Holmesburg Junction and stay in tough with the CB. Jimmy would go to one end of Holmes Interlocking and I would hang out at the Tower.

The "kiddie" walkie-talkies used a super-regenerative receiver, ie; a positive feedback design -- no real squelch circuit.

The "pro" CB HTs did have a squelch, but being an AM signal (in which the modulation basically varies the signal strength) don't have a sharp cut-off.

Posted
2 hours ago, WRXE944 said:

Does your 878 do GMRS/MURS too?

It’s a dual band radio. Using the right passcode in the programming software allows changing the band limit configuration to cover the required frequency range.

The important question is it legal to use the radio to transmit on those services. Without qualification the answer is no. Anybody who does should understand this fact. After that it’s up to them what they choose to do. It’s not my job to play the part of a radio cop.

About dPMR you can find info on the Internet. As far as I know there is nothing that prohibits its use here. When digging around for information on it I haven’t found a definitive reason why it’s not used in the US at least. My guess it’s just a marketing issue and more importantly which CODEC is used.

The dPMR standard has THREE different and incompatible CODECS specified with an optional vendor specific one allowed. Whereas DMR, NXDN and P25 all use a specific one, AMBE+2, regardless of manufacturer. This ensures radios using the same protocol can inter communicate between manufacturers using compliant radios. That wouldn’t be true for dPMR radios.

dPMR MoU tech lib Voc Bits V1 (2019).pdf

Posted
1 minute ago, WRXE944 said:

Let me switch two of your paragraphs around and then ask you a question:

So dPMR is legal to use here in the USA; on which service(s)?

It should be legal to use on the Ham bands here. It’s an open standard that’s published so nothing is secret about it.

I would imagine it’s also legal for Part 90. It’s a FDMA modulation emission, just like NXDN which is already used here, but the frequency shifts are a bit different and the digital protocol is too. The bandwidth is the same as the very narrow NXDN mode and fits into the same 6.25KHz channel allocation. The occupied bandwidth of both is only 4KHz.

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