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Posted

Speaking from a technical standpoint, Given the wattage and how VHF signals travel vs how UHF signals travel, it wouldn't be feasible. You can take UHF on 2 watts and make the signal travel a good distance. Take VHF and try to do the same and you usually wont get the same thing. Usually when they link repeaters together they use a UHF frequency to link two or more VHF repeaters together. I have only encountered one time when a base was linked to a UHF repeater through a VHF crossband and that was for a business. The distance that 2 watts of VHF power would cover to connect two UHF repeaters together would bring both UHF repeaters coverage areas together to where it would make more sense to just to use one UHF repeater to cover both areas.

IF you broke the rules and used high power on VHF with directional antennas, YES, you could link two repeaters.

Honestly, I wish the FCC would take the MURS band and allow GMRS operators to use it to link things together. BUT, that's what Ham radio is for. The sad part is that I find more enthusiastic guys on GMRS who would love to do this but don't want to go through with getting their Ham license because of the politics. In Ham Radio where you have all of the ability in the world to do high power, crossbanding, linking, repeating etc........... no one really experiments with anything like that. I love getting into that stuff, no one else does. That's why I have reverted to leaving my radios shut off and I watch TV in the other room. Much more entertaining.

Posted
2 hours ago, WRQI583 said:

Usually when they link repeaters together they use a UHF frequency to link two or more VHF repeaters together.

IMHO I think that has more to do with more spectrum is available on UHF. Using VHF for a link would use up more of the limited VHF spectrum for repeaters.

  • 9 months later...
Posted
On 2/15/2023 at 11:45 AM, gscanter said:

Would it be legal to use MURS (with correct band width an power output) to link two GMRS repeaters? Opinions?

 

  1. On 3/2/2023 at 6:55 PM, Adamdaj said:
    1. According to the FCC's Rules and Regulations that would be Big NO. Just as the name implies, the Multi Use Radio Service was created for commercial and noncommercial use, even though MURS is in part 95 J.
    2. FM     
    3. Voice 
    4. Data   PC to PC Texting
    5. Image  

I just reviewed my reply and sounds like I've been either have been drinking or my mind was on a coffee break. Of course, questions such as this one is asked once in a while. As for the question posted by gscanter 15 Feb of 2023. What I meant to say, according to the FCC's Rules and Regulations. The short answer would be a Big No, because the FCC intended for MURS to be used for multipurpose, either for commercial use or non-commercial use. According to the FCC's Part 95 J, it is forbidding to crossband MURS with GMRS simplex or repeater. However, there have been individuals who have set up temporary crossband simplex systems using MURS and GMRS channels, which still violates Rules & Regulations. 

 

 

  • 5 weeks later...
Posted
On 2/15/2023 at 1:22 PM, gscanter said:

It would not be a MURS repeater in the normal sense of the word.  It is just forwarding the audio in simplex mode between GMRS repeaters.

 

This would be acting as a cross-band repeater, which is, unfortunately, covered by that prohibition.  

Don't feel too bad, I have six MURS handies, three base stations, and a mobile from a similar project.  Just … I would rather carry a tiny UHF radio than the brick of a VHF one.  Still pull them out when GMRS is full of noise or when shopping, though!  

What might work, if you need a fully unlicensed or minimally-licensed system is using Motorola DTR550 radios for the backhaul.  Sure, you're limited to one watt, but it's digital spread spectrum, interference resistant, and one watt into a tight-beam Yagi makes the EIRP a whole lot higher than one watt if the antenna is pointed directly at you.  The DTR550 is an older radio, but it has swappable antennas, which makes it our Goldilocks radio here.  You'll also want a couple DLR1020 or DLR1060 radios to monitor what's going out over the inter-site beam, plus you'll be able to use it as a compact speaker-mic to access your big fifty-watt base station radio from wherever you are in your house.

Posted (edited)
On 2/22/2023 at 9:06 AM, gortex2 said:

I love how folks get on forums and try to change services that have been in place for years to make it do what they want to do vs finding a service to do what they want to do. 

To be fair, there frequently ISN'T a service that does what we want.  I mean, it's 2024, and only NOW is there an elegant way to put the radio I want in the truck I have, and I've been scouring the market since 2015!***  

 

It'd be a buttload easier if all my family had ham licenses, but my mother, for example, has been sitting on the ham radio book I got her at her request for five years now.  She never did get around to putting up the TV antenna which the book was supposed to help her pick, either…  In total, I have one uncle with a lapsed callsign, and nobody else will even use Zello, for fuck's sake!  

 

My mother even resisted using radios back when FRS was new-ish and I scored a couple Radio Shack handies for an insanely good deal when we were trying to figure out which breaker in the box turned off the outlet we needed to replace.  She just … carried the radio, but shouted across the house, then had the temerity to give me shit when I couldn't hear her.  She's well and truly over that obstinate phase, but still won't put any cognitive effort into scrolling through HamStudy for an hour and taking a fifteen question test…

 

*** PS:  I'm not permitted to drill holes or fuck up the paint.  That means I need a $330 drop-in antenna that replaces the stock antenna, and a Vero VR-N7500 radio hidden in the dash.  The hand-mic will be run to a knockout panel in the dash with a CAT5 patch cable.  The control panel for the radio will be provided by either a Carpuride CarPlay display which pulls double-duty as an Android tablet when no phone is available, or a Joying drop-in touchscreen head unit.  Again, primarily CarPlay and Android Auto, but runs Android apps when nothing is plugged in.  When you're not using the app, the radio wisely limits you to flipping through a single bank of sixteen preset channels, and turning the volume up and down; you shouldn't be doing any more than that while you're driving along at highway speed anyway!  The final result is a COMPLETELY REVERSIBLE mod with ZERO drilling or wire splicing; the fist-mic either plugs into a jack next to the factory-installed USB charger, or is completely wireless and connected via Bluetooth.  The software integrates APRS signaling; it may integrate with a turn-by-turn direction function, giving J. Random Ham (that's me!) the functional equivalent of a police dispatch system, so you can keep an eye on anyone you're caravanning with.  Compare this to the (MURS-based) Garmin Group Ride Radio's functionality -- Garmin has absolutely the software stack I want to use here, but god DAMN is that expensive to install, and it's not compatible with the normal stuff I do on a car stereo.  $350 for the radio unit, plus $600-1500 worth of fancy GPS navigator.  And I'd still need a drop-in VHF antenna for it!  So add another $330 for that.  $1850 for an all-in Garmin setup to track people you're driving with, or $198 for the ham solution.  Other per-vehicle costs -- $330 antenna, $30 dash passthrough, $?? fuse tap for power, are all fixed.  Between $100 and $400 to modernize the car stereo which is really nice (but not quite mandatory) for the ham solution, but still required for the Garmin, since it won't do carplay.  

As it turns out, even the military couldn't get that technology for love or money until several years ago when they developed and open-sourced ATAK -- the Android Tactical Assault Kit, since re-christened the Android Team Awareness Kit, now that it's capable of operating as a full-fledged GIS and not just a blue-force tracker -- basically they added some really useful disaster-relief functions into the software!  Amateurs had something like this using APRS, but historically APRS transmitters were small, "cheap", and easy to integrate but receiving APRS broadcasts required a dedicated antenna, radio, and a PC or Mac, which is … non-trivial to install into a modern car!  A friend's father actually DID that, but it took waiting until retirement until he had the free time and money to do the necessary engineering work to make it happen.

Edited by Ian
Added lots of context with a post-script
Posted
7 hours ago, Ian said:

To be fair, there frequently ISN'T a service that does what we want.  I mean, it's 2024, and only NOW is there an elegant way to put the radio I want in the truck I have, and I've been scouring the market since 2015!***  

Correct. This is the issue. This service doesn't do what you want but you don't want to use another service for a multitude of reasons. That's not a reason to change this service. There are services that do what you want, either amateur, LMR or broadband. All of which can be done if you want to. 

As far as the radio issue you seem to have the radio posted is ham radio and not GMRS so why is that ultimately the perfect radio ? You plan to use ham now after saying you can't use ham ? Are you planning others in your caravan to also get ham license so you can use APRS ? 

In the end HAM will do what you want but everyone needs to be a ham to take advantage of it. 

  • 1 month later...
Posted
Quote

 

you don't want to use another service for a multitude of reasons

Well, all the other services available to me at the time would involve SOME form of freebanding.  The most performant option I was considering was importing a European Midland CB with FM mode -- it isn't hard to find unused spectrum on there, and with FM for voice quality and CTCSS for squelch, it would have provided the most critical car-to-car voice comms that I need for the occasional road trip or cargo hauling.  Instead, we went with an eye-wateringly-expensive eight-hour cellphone call, back when "minutes" cost money!

Also, it's only EXTREMELY recently that good tac-net software (APRS apps) can run well on a $40 tablet, and car stereos can run said apps.  Like, it was 2023 when Carpuride introduced a CarPlay retrofit display that could run Android mapping software natively.  

Quote

why is that ultimately the perfect radio ?

Because the Baofeng GMRS Pro is a type-accepted, software-locked version of that radio which I can hand to "limited users" without fear.  I've got my GMRS license, sure -- but it motivated me to get my ham tech license not long after.  My mother is interested in getting her ham license eventually, and was supposed to be looking at my study guide to help her pick out a broadcast TV antenna, but she's been doing that for the last seven years!  

No, the reason is sadder.  I just lost a lot of friends to middle age problems, and now there's only one friend that I might want to communicate with via RF, and he'd be easy to persuade.  :(  Just normal shit like moving, incompatible work schedules, hobbies drifting apart.  (In my case, I just can't afford to participate in Warhammer, which makes ham radio look CHEAP!  I was gifted a Warmachine army by the friend who moved to New York, but I'm just barely getting into that.)

 

Quote

 

In the end HAM will do what you want but everyone needs to be a ham to take advantage of it. 

Only now that the mobile clients have gotten good.  Actually? The BEST match to my desires for a mobile radio that I've found so far is the Garmin Group Ride Radio… Problem is it's a $350 MURS radio which requires being paired with a minimum $500 GPS device.  It'd be easier to convince everyone to get ham tickets than to shell out $850 + tax + shipping!  😕  And that's the small screen one; bigger ones go up to a $1500 bundle.  

Quote

broadband

Only since T-mobile got their 600 MHz spectrum are there no longer cellphone dead-spots on my weekly commute.

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