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GMRS (General Mobile Radio Service)

Discussion in 'Audio & Video' started by Prerunner1982, Aug 30, 2017.

  1. Aug 30, 2017 at 2:53 PM
    #1
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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    A valid alternative to the CB radio?

    The CB radio has been the go to radio for offroad enthusiast for decades because at the time it was the best option that didn't require you to test and know morse code. Today there are more options but most offroaders are still using CB. Why?

    Ok I know there are people who are scared of the ham test (though it no longer requires morse code) and there are people whole don't like Government rules/control or giving the government money... I get it, but for the rest of the population there are other alternatives.

    Though GMRS does require a license there isn't a test. The license is good for 10 years (after 9/28/2017), cost $70, and covers your immediate family. Figure that is $7 a year, forgo a couple of lattes every once in a while and you will have that $70 back in no time.

    GMRS also shares it's frequencies with those little handheld radios you can purchase at any major retailer. Those handheld radios are in the Family Radio Service (FRS) and while they share the same frequencies they are lower power, 2 watts or less. GMRS allows up to 50 watts and there are small mobile radios available, but they are capable of working with each other which makes the FRS radios great spotter radios.

    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.
    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.

    Right now Midland is the only company I have found producing GMRS mobile radios. The 5 watt MXT-105 is $100, the 15 watts MXT-115 is $150 and the 40 watt MXT-400 is $250.
    Midland does occasionally offer a 20% off promo code.

    Unfortunately it seems people are reluctant to change, even if something better is available. Maybe it's because a lot of people don't know there are alternatives... I don't know.

    If you have any questions, let me know.
     
    Last edited: Aug 31, 2017
    JKBob 25 and chris4x4 like this.
  2. Aug 30, 2017 at 3:29 PM
    #2
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine Moderator

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    What's the range with these systems versus CB?
     
  3. Aug 30, 2017 at 4:07 PM
    #3
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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    They are both line of sight (not counting CB skip which isn't reliable) so their distance should be about the same, however terrain and surroundings play a roll so there isn't a definite answer here.

    But let's take in to consideration that offroaders generally don't run 108" whips mounted in the center of the vehicle, so running a 3 or 4' antenna is a compromise and then mounting it somewhere other than center of the vehicle is a compromise and was it tuned? (compromise).. does it have sufficient ground plane? (compromise)... and you end up with a radio that can talk a couple of miles at best.

    Put a 6" GMRS antenna on top of the windshield, roof rack, or a mount above your spare tire, not only is it mounted up high, but in most cases will have sufficient ground plane and you will be able to talk at least a couple miles if not much more. Using a longer antenna will increase the gain of the antenna allowing you to potentially talk further.

    I have led a convoy of 75 Jeeps and most people couldn't talk from one end of the convoy to the other with their CB. Though myself and a few others were using VHF ham radio with no issue I have no doubt that UHF (GMRS is just outside the UHF ham band) could have done just the same.
     
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  4. Aug 30, 2017 at 5:27 PM
    #4
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine Moderator

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    What do you run? Do you have a preference, and what should you look for when/if going this route?
     
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  5. Aug 30, 2017 at 6:15 PM
    #5
    JKBob 25

    JKBob 25 Well-Known Member

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    Very interesting. Thanks Prerunner. I'm subbed.
     
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  6. Aug 31, 2017 at 6:13 AM
    #6
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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    Personally I run ham radios. If I didn't GMRS would be my next option and I may still run a GMRS radio now that the license is 10 yrs and it covers the entire family which is something I forgot to mention earlier but have updated my original post to include. There are commercial radios that are allowed to operate on GMRS but they require special software to program and most end users aren't going to want to deal with that. As far as plug and play Midland pretty much has the market cornered, unfortunately. And as such the cost of their mobile radios is a bit high. Their earlier MXT radios (90 and 100) did not do repeaters while the newer models do, but for simplex (radio to radio) communication that doesn't matter. All of their radios do have the NOAA weather channels, except the MXT400.
    GMRS.jpg

    Ham radios can be modified to work on GMRS frequencies though not legally. Some of the chinese ham radios are already open to transmit on those frequencies. If they were programmed correctly with the appropriate power outputs and such, nobody would know unless you told them. Ham radios are cheaper than the Midland radios, heck the MXT400 looks identical to ham radios currently on the market. Not that I am recommending or condoning illegal use.
     
    Last edited: Oct 10, 2017
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  7. Aug 31, 2017 at 7:20 AM
    #7
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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    Jumping back to range, this is what Midland shows:

    GMRS distance.jpg

    Max 50 miles? What they don't tell you is that each antenna must be about 300 feet above ground. This is due to the curvature of the earth. With two antennas 6' (top of vehicle) the line of sight communication distance would be about 6 miles. However, the density of the atmosphere can allow the radio waves to bend slightly and increase the radio horizon some beyond the geometric horizon.
     
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  8. Oct 31, 2017 at 9:22 AM
    #8
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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  9. May 14, 2019 at 8:03 AM
    #9
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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    Looks like Boafengtech has jumped on the GMRS mobile market, 50 watts for $179.89. https://baofengtech.com/gmrs-50x1

    Glad to see someone else producing a mobile GMRS radio, hopefully a little competition will bring the prices down.
     
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  10. May 17, 2019 at 4:58 AM
    #10
    TJ_abuser

    TJ_abuser Well-Known Member

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    You said it's a frequency modulation radio ? That should go a lot father than am due to fm signal bounces and an am followers the earth (line of sight) . Especially on a good cloudy day it should bounce at least 20 miles I would think. We had FM radios in the army that went father than a couple miles. Come to think of it the ARN 82 and the ARN 52 are fm but receivers .
     
  11. May 17, 2019 at 5:01 AM
    #11
    TJ_abuser

    TJ_abuser Well-Known Member

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    The ham will go a lot father and cost about the same don't it? If that's the case I'll just go the ham route the license looks supper easy now. Did you have to pass the Morse code test Jon?
     
  12. May 17, 2019 at 5:29 AM
    #12
    aggrex

    aggrex Well-Known Member

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    I'm far far from a ham expert..... think I read that the morse code requirement is gone. Correct me if I'm wrong fellow hammie
     
  13. May 17, 2019 at 5:51 AM
    #13
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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    It is FM but the frequencies used are still line of sight, they sound better though due to being FM vs AM. GMRS is 462Mhz and 467Mhz.

    It depends on the frequency but most ham frequencies you would use would be VHF/UHF and still be line of sight however as I stated above the audio qualify is better (FM), you also have a few more watts (generally 50-85). Ham also has many repeaters to use, some linked to other local repeaters, some linked around the county/world. Another benefit of ham radio and more so GMRS radio is the size of the antenna and the smaller ground plane needed vs CB.

    With some of the Chinese radios on the market you can get into either of the 3 radio services for about the same cost, GMRS may be a bit more expensive for now. However, even a 2m mono band radio from Kenwood or Yaesu (big names in ham radio) can be had new for as much or less than a big CB. Some of the big CB radios near the price of some dual band (2m and 70cm) ham radios.

    The Technician (entry level) test is easy and the Morse Code (CW) requirement was dropped in 2007 for all amateur radio license levels.
     
  14. May 17, 2019 at 6:31 AM
    #14
    jeepavalanche

    jeepavalanche Active Member

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    GMRS vs CB. I can say, while a CB has its limitations, I can put a 500 watt amp on mine and get out 20 plus miles talking clearly and hearing those that are amped as well. Does GMRS have the ability to run an amp? If so, that would be the better option.
     
  15. May 17, 2019 at 7:17 AM
    #15
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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    GMRS is up to 50 watts only.

    I've done 10 miles on 2.5 watts on CB but most off roaders don't have a well set up system.
    They run short antennas mounted in poor locations with poor ground planes. They are lucky to talk a 1/2 mile...from my experience anyways.
    GMRS is more forgiving of little ground plane and the antennas are already super short but you can get longer antennas for more gain if so desired.

    I have talked all over the world on 100 watts or less. You can talk to the International Space Station on 5 watts from a handheld radio at 254 miles.
    GMRS (UHF) is line of sight regardless of how many watts you are throwing at it the earth is still curved.

    If an amped up CB works for you then that's all that matters, it meets your needs.
     
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  16. May 17, 2019 at 7:34 AM
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    jeepavalanche

    jeepavalanche Active Member

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    Well, ideally what I'd like to have is something that has a big community of users, and have the ability to get out long range. As of right now, I can talk to people 50 miles away from me on CB if they are also running an amp. CB has a lot of users, but I don't like to have that big unsightly antenna on my vehicle. If those little hand held radios gain popularity with the public, and can have long range, then that would be the ideal way to communicate.
     
  17. May 17, 2019 at 9:02 AM
    #17
    Prerunner1982

    Prerunner1982 [OP] Well-Known Member

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    I would like to see more groups change over to GMRS for real trail/convoy comms but it is very slow to happen and some just can't get away from their 1970s technology for multiple different reasons.
    So unfortunately GMRS has some users but maybe not what I would call a big community of users especially those with higher power mobile radios. Most GMRS users carry the little handheld radios you see at Walmart/Bass Pro and while they work they are not the best option especially mobile. For VHF/UHF frequencies (Ham or GMRS) antenna height is king for distance so a little GMRS handheld with a 3" antenna inside a vehicle (metal cage) just isn't going to do much outside of a small group of vehicles.

    Ham radio has a much larger community of users many using mobile radios and access to many repeaters across the country.
    If you really want long range you would need to get a General class amateur license and an HF radio to talk across the country/world.
     

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