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FRS/GMRS Radio Help Please

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  • FRS/GMRS Radio Help Please

    I was at Sam's club today and picked up a set of Motorola T6510 FRS/GMRS radios. I picked these up because I wanted better range and I thought they might be a better option than the FRS only radios I have now. I use the radios for communicating between cars on the road (The FRS radios appear to be good for about a 1/4 mile direct line of sight.), around the cabin in the woods and while camping, and from shore to boat on the lake.

    Here are the questions I should have asked before I bought them:

    1.) You are supposed to have a license for GMRS channels but I saw a post that the GMRS channels may be going the way of CB where licenses will not be required. If using these without the license is like going five over the speed limit then I don't have a problem with it but I don't want to be an ouitlaw either. Although it seems to me that if the FCC wanted them licensed they shouldn't have allowed them to mass marketed the way they have been. What's your opinion on this?


    2.) There are some channels listed in the manual as FRS channels (462.5625, 462.5875, 462.6125, 462.6325, 462.6625, 462.6875, 462.7125) but apparently these radios transmit at 1 watt on those channels rather than .5 watts and you are supposed to have a license for that. My question is, how could anyone tell?

    3.) In order to be able to talk to someone on the FRS radios I have, you basically need to be within a 1/4 mile of them, line of sight, while driving; how much better is the distance going to be with 1 watt or on GMRS?

    4.) These radios do not have seals around the battery compartments (my Cobra FRS radios do), how susceptible will they be to moisture if I'm wearing one on my belt in the rain or out on the ski boat?

    Aside from a little more power, the only other feature these have my Cobra radios don't is that if there is an emergency weather broadcast they will jump in and broadcast that.

    Thanks in advance for your help!

  • #2
    1) Depends on who you piss off and how much of an ass you are about it. If you aren't hogging an in-use channel and beiing a general pain, few will care. If you're using them for car-car, you'll not be in an area long enough to really annoy anyone either.

    If you are annoying and using them in a relatively fixed area, someone will eventually complain. I believe the first step is usually an FCC cease & desist type letter. Continued unlicensed and annoying behavior can result in fines & confiscation.

    No, you don't want the .gov to step in and say you can't buy this or that unless you are licensed & approved - bad precedent.

    2) Normally a FRS/GMRS radio will only transmit at full power on the GMRS channels. To get FCC approval, they have to reduce their transmit power on the FRS channels to the legal FRS limits.

    How can they tell? Your signal will reach further and be louder close-up. (some older GMRS radios do transmit at full power on FRS freqs, so you'll run into this now & again)

    3) If I recall properly, radio propogation is like sound propogation - to double the volume, you need to square the power. You will notice a better range with unobstructed line of sight, but hills, greenery, etc will still reduce your range dramatically. (damp foliage is the worst for reducing range)

    4) sorry - not a clue on this one.
    Killing for the sake of honor is no longer allowed in our decadent society<br /> more\'s the pity, as it would greatly improve manners.<br />- - - - -<br /><a href=\"http://www.cloud9photography.us/\" target=\"_blank\">Airplane Pictures</a><br /><a href=\"http://crankylabs.com/gallery\" target=\"_blank\">Cranky Labs Image Repository</a><br /><a href=\"http://www.a-human-right.com/\" target=\"_blank\">A Human Right</a><br /><a href=\"http://www.olegvolk.net\" target=\"_blank\">Oleg Volk Photography</a><br />- - - - -<br />I\'m Amish Bill, and I approved this message.

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    • #3
      Thanks Amish Bill, I really appreciate your insight. I think I will return these and wait for things to change or look at another system. How well do the handheld CB's do?

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      • #4
        Being a HAM operator I am somewhat biased in that direction, but, having a fair amount of experience with both CB and FRS I'll put my .02 cents worth in.

        Handheld CB's operate in the AM mode where FRS/GMRS and HAM HT's are in the FM mode. Both modes have their pro's and con's.

        AM has a better range under some conditions but is prone to noise and static as well as skywave reflected signals.. AKA skip. CB's are not as effected by some of the "line of sight" problems that occur at the much higher frequencies where FRS/GMRS/HAM operate.

        FM provides a clearer signal with much less interference by static from power lines or natural sources and due to the high frequency is not prone to skywave reflection.

        The HIGHER the frequency you use, the MORE you will be restricted to "line of sight". Example: Microwave Relay Systems, such as the phone company uses MUST have a DIRECT "LOS" to operate. These are the parabolic reflectors yo see on cell towers as well as the numerous towers required in a given area to provede cellular coverage.

        As a comparison:
        CB freqs are 26-27 MHZ -HF band- 11 meters.
        HAM freqs 144-148 MHZ -VHF band- 2 meters.
        HAM freqs 420-450 MHZ -UHF band- 70 CM
        FRS/GMRS freqs +/- 460 MHZ -UHF- &lt;70 CM
        CELL is around 900 MHZ -SHF- ~32 CM

        CB has 40 Channels
        FRS/GMRS have 15-20
        HAM has hunderds of frequencies.

        CB is limited to &lt;5 watts.
        FRS/GMRS is limited to &lt;1 watt
        HAM HT's are limited to 5-7 watts tops but you can go higher with a mobile rig to 50+ watts.

        Now on the line of sight issue...
        CB's will either make it or they won't. If the skip is heavy or theres a lot of static then you're out of luck. When conditions are good then you get fair range.
        Same is true for FRS/GMRS. You have to deal with it...
        HAM bands utilize repeaters to extend the range of HT's and mobile rigs. Many repeater systems are linked together for statewide coverage. Others are localized to a particular county or city.

        YES the HAM bands DO require a license but it's mostly common sense questions and a little memorization. --I know 10 year olds with a ham ticket-- The understanding of radiowave propagation and "how radios work" that comes with the hobby is worth it's weight in gold..

        I know this got a little long winded but I hope it gives you a better concept of radios. There is NO "PERFECT" radio or band for all conditions or situations so an educated choice is in order given what you want to do and the demands you have for commo.

        Amish Bill, myself and others here will answer your questions as best we can so feel free to keep posting them.

        Cheers...JW...

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        • #5
          CB handhelds - for the same range as FRS you're looking at a much larger unit that will eat more batteries faster. Unless talking to car-mounted CBs is a big point for you, there's no practical criteria where a CB handheld will win over FRS.

          If you look, you can still find the old Radio Shack cigarette lighter powered, outside of the car magmount FRS units. They've been discontinued for some time, but they're still out there.
          Killing for the sake of honor is no longer allowed in our decadent society<br /> more\'s the pity, as it would greatly improve manners.<br />- - - - -<br /><a href=\"http://www.cloud9photography.us/\" target=\"_blank\">Airplane Pictures</a><br /><a href=\"http://crankylabs.com/gallery\" target=\"_blank\">Cranky Labs Image Repository</a><br /><a href=\"http://www.a-human-right.com/\" target=\"_blank\">A Human Right</a><br /><a href=\"http://www.olegvolk.net\" target=\"_blank\">Oleg Volk Photography</a><br />- - - - -<br />I\'m Amish Bill, and I approved this message.

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