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New Repeater Channels for GMRS in 2024


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One can absolutely run digital and analog on the same repeater as long as everything is setup correctly. This is done all of the time with 70cm repeaters using analog and DMR.

Now if the settings are not correct, then the digital side can interfere with the analog side and visa versa. 

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1 hour ago, WRYZ926 said:

One can absolutely run digital and analog on the same repeater as long as everything is setup correctly. This is done all of the time with 70cm repeaters using analog and DMR.

Now if the settings are not correct, then the digital side can interfere with the analog side and visa versa. 

We do this with a 70 cm repeater here.  There’s not a lot of traffic for either digital or analog and it’s first come, first served.  Seems to work just fine.

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On 5/28/2023 at 7:49 PM, Adamdaj said:

DMR on the General Mobile Radio Service Band sounds good, but not all GMRS users are really familiar with DMR. I mean not all GMRS license holders are also Amateur Radio License holders. I do forget the one manufacture of an FRS radios that have digital capability, but what format ? I want to say Retevis, but I could be wrong. Anyway, I know it isn't any of the other manufactures, such Midland or Motorola. Of course, I would sell all the vertex radios I own to buy Motorola GMRS Mobile if they came out with one, but I have better chance of seeing the Dodgers move back to Brooklyn before Motorola produce a GMRS mobile radio. I kind of dabbled with on FRS low power of course, just to hear my voice over my Scanner. I used channel 01 and 07 just brief test which is technically violating FCC regulations somewhere, but I would not use it unless the R&R changes to allow.

That was the Retevis RT-40; I own four of them.  They sound shockingly good, even on analog channels; I'd like to firmware unlock them for amateur radio frequencies though.

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  • 4 weeks later...
  • 4 weeks later...

What do you work for Motorola? This is what "M" did to volunteer FD's with no budget, forced P-25. Horrible audio (like DMR), expensive equipment, and a programming laptop and cables. I'll keep my clear, wideband GMRS frequencies where I can use a Midland VFO MXT400 or if I want to program a Kenwood mobile with WB capability. If you want DMR get your ham license and stay there. 

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1 hour ago, WRUQ758 said:

What do you work for Motorola? This is what "M" did to volunteer FD's with no budget, forced P-25. Horrible audio (like DMR), expensive equipment, and a programming laptop and cables. I'll keep my clear, wideband GMRS frequencies where I can use a Midland VFO MXT400 or if I want to program a Kenwood mobile with WB capability. If you want DMR get your ham license and stay there. 

haha that’s a good one 😂 

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1 hour ago, WRUQ758 said:

If you want DMR get your ham license and stay there. 

I think we’ll get digital in some limited form sooner or later on at least some of the GMRS channels. It might not necessarily be DMR.

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I think digital is coming I know midland has been bothering the FCC for it for a good amount of time. It is just whether they budge. Midland wants to do some sort of DMR like system for their radios ive seen the filings a few times but I cant remember if the FCC approved any I will have to go dig again.

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There is already unlicensed digital, analog or mixed modes on a couple of GMRS repeater input frequencies - it's just not GMRS. It is for "On-Board Vessel Communications" and covered under ITU (ITU-R M.1174-4) regulations in conjunction with the FCC. Since the band and channel plan already exist, it would be cool to open it up to GMRS.

 

itu.JPG

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On 6/30/2024 at 12:04 AM, Lscott said:

I think we’ll get digital in some limited form sooner or later on at least some of the GMRS channels. It might not necessarily be DMR.

I myself hope its DMR, but if its IDAS / NXDN. That would be great. I could buy a dual band radio to program in GMRS systems and be able to monitor the AAR Channels for Railfanning. This way I can rag-chew with other GMRS users that may also be into the Railfanning hobby as well. Of course, Amateur Radio Operators do that all the time. Of course, you are not monitoring and talking at the same time, but you can share information about trains that you and your buddy maybe following. 

It used to be a Railfan tools were times table, a camera and a VHF Scanner or Two-way Radio with Transmit Disabled. Now, it's a IDAS or NXDN Two-way Radio or Scanner and an app for the map display the territory in which you're tracking the Rail Activity, Last but not least, the camera and the snacks soda pop or coffee.

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5 hours ago, Adamdaj said:

I myself hope its DMR, but if its IDAS / NXDN. That would be great. I could buy a dual band radio to program in GMRS systems and be able to monitor the AAR Channels for Railfanning. This way I can rag-chew with other GMRS users that may also be into the Railfanning hobby as well. Of course, Amateur Radio Operators do that all the time. Of course, you are not monitoring and talking at the same time, but you can share information about trains that you and your buddy maybe following. 

It used to be a Railfan tools were times table, a camera and a VHF Scanner or Two-way Radio with Transmit Disabled. Now, it's a IDAS or NXDN Two-way Radio or Scanner and an app for the map display the territory in which you're tracking the Rail Activity, Last but not least, the camera and the snacks soda pop or coffee.

Did you see this?


https://groups.io/g/RailScan/files/NX-200 Railroad 20220422.dat

I have some NX-200’s and did a prototype code plug for one for railroad scanning. Not enough railroad activity by me to test it out.

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17 hours ago, Lscott said:

Did you see this?


https://groups.io/g/RailScan/files/NX-200 Railroad 20220422.dat

I have some NX-200’s and did a prototype code plug for one for railroad scanning. Not enough railroad activity by me to test it out.

I couldn't view the Rail Scan Files, because I don't have a groups io account. Thank you for sending to me. Of course, I already know the majority of class 1 Freight Railroad Companies are equipped for IDAS / NXDN, though they still operate in analogue mode. While Radio Reference Site, I notice under Florida Railroads Radio channels. I wasn't actually sure whether it was the Florida East Coast or another Short Line that are currently using DMR repeaters on AAR Channels

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2 hours ago, Adamdaj said:

I wasn't actually sure whether it was the Florida East Coast or another Short Line that are currently using DMR repeaters on AAR Channels

That’s odd. I thought it was settled the railroads would move to NXDN. Then they sort of backed off sticking with analog FM. The reason I read was a lot of track side equipment is tone controlled, which the railroads found out doesn’t work that well with NXDN.

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23 hours ago, Lscott said:

That’s odd. I thought it was settled the railroads would move to NXDN. Then they sort of backed off sticking with analog FM. The reason I read was a lot of track side equipment is tone controlled, which the railroads found out doesn’t work that well with NXDN.

I thought you meant for Train Crews and Dispatcher Comms. I didn't think about the Wayside Detectors or Mile Post Recorders. I forgot the YouTube Channel, but the presenter was doing a small demo on the Whistler Scanner. I'm pretty the presenter was monitoring the Norfolk Southern yard in South Caralina or Georgia, but I'm sure the Train Crews were assembling and disassembling Trains. I don't remember the exact AAR Channel, but I'll take a guess, it was either AAR CH 75 161.235 or AAR CH 91 161.475.

Of course, the scanner had everything in one price, un like UNIDEN, where UNIDEN charges for DIGITAL FORMAT KEYS. If you were look up AAR Channels for Class 1 Railroads, the Ritron is replacing the Motorola Train Master or Locomotive Spectra for Locomotive Cab Radios, since Motorola doesn't have a line of compatible radios for IDAS/NXDN Format.  

Speaking Short lines / Tourist Railroads, I do know that New Hope Ivy land has started to use IDAS/NXDN on AAR CH 91. The NHIRR also has AAR CH 21 assigned to them, so at some time, I'm sure they're have their IDAS/NXND Repeater online at some point. When I do hear NHIRR, they're usually requesting permission to occupy the Warminster Runner to switch Double H Plastics or the Pasta Plants south of Warminster Train Station.

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I also stumbled across a thread for fire fighters. The concern there was the background noise, sirens - air horns etc. The vocoders used for P25, NXDN and DMR is very highly optimized for human speech only. The above mentioned sources of background noise tends to muck up the vocoder and the resulting sound quality. It was also the reason given for some of the unsatisfactory results trying to run track side tone control through NXDN.

If you know anybody with a NX-200 radio I've attached the prototype railroad code plug. Don't need a "groups.io" account. This is a short description of the code plug.

-----------------------------------------------------------------------------

Code plug for Kenwood NX-200 radios with all the standard VHF analog and digital channels included. I understand the NX-210 is almost the same radio.

This is a prototype and has not been tested. No passwords are used. To aid rail fans the 5 MURS channels are also programmed in too. MURS is a license free VHF radio service. The default power level is set to 5 watts while the legal max allowed is 2 watts. If you want to stay under the legal power limit then select low power, 1 watt, using the programmed function keys on the front panel.

This version a number of Ham 2M simplex frequencies were added in for those licensed for this service. The channel names match the frequency programmed in to that memory location.

The seven NOAA VHF weather channels are also programmed too. The transmit function for these are disabled.

To program the radio you will need a copy of KPG-111D software. NOTE all the channels have transmit ENABLED! If you don't want this then you have to disable the transmit function yourself. -------------------------------------------------------------------------------

The NX-200 is very similar to the NX-210, which is the railroad version, which seemed to be favored by rail-fans.

NX-200 Railroad 20220422.dat NX-210.pdf NX-200_300.pdf

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Let keep talking about it like it's a good thing to go digital instead of people understanding that gmrs is not a "hobbyist" radio service. People think Simulcasting is ok, and look what happened in NY. If you want all this extra crap just go Amateur radio.


Sent from my SM-S918U using Tapatalk

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4 hours ago, wqnd300 said:

Let keep talking about it like it's a good thing to go digital instead of people understanding that gmrs is not a "hobbyist" radio service. People think Simulcasting is ok, and look what happened in NY. If you want all this extra crap just go Amateur radio.


Sent from my SM-S918U using Tapatalk
 

Yeah,  what's going to happen is as the GMRS user base grows and more repeaters go on the air, it will get to a point where people will start complaining to the FCC about their repeaters they just put up are being interfered with by other established repeaters.  The FCC is going to react at that point.   Since the frequencies we are using sit in the middle of the commercial band that is saturated with users in about every urban area there are NO additional frequencies available for the service. 

So how do they react?  They can go back to assigning repeater pairs to the license holder.  Only allowing the license holder to have 2 pairs, one being 462.675 (traveler) and one other pair. 

They can narrowband the service and take it to 12.5Khz channel spacing.  This takes all the older wideband only radios and removes them from being used on the service. Now MOST radios built in the last 20 years will work with that channel spacing.   But be warned, you will LOOSE at least 1/3 of the coverage foot print of all repeaters when they are switched.  Of course that also doe's something for the interference issues since the repeater coverage drops.

Or, they can break in off in us and take the whole service to 6.25Khz channel spacing, which would remove the ability for MOST of the current radios to be used.  Effectively making everyone buy a new radio to operate on the service.  But I am talking that even Motorola XTS /XTL radios will go away.  If you want a Motorola radio, your getting an APX at over a grand each minimum.  But all the BTech, Midland, ETC ETC stuff will be illegal to operate.  You can have more channels, but you now loose 2/3 of the current wideband coverage footprint of the repeaters.  And of course it's not just the repeaters... simplex coverage will suffer just as bad.

Lastly, they could really do us dirty and go the way many on here seem to want them to go and allow DMR or some other digital format.  Problem with that is again, new radios as all the current GMRS specific radios like BTech and Midland are analog only and will not support digital modulation.  So again we buy new gear that's not going to be cheap since there are license fee's to be paid for the vocoder in the radios that exceed the cost of a new BTech for just the license.  Then we get to the interference issues from adjacent repeaters.  With analog, you get hetrodyne first,  then there is some noise and audio quality issues before the signal gets bad and the interference gets to the point that you can't understand the repeater you are listening to.  With DMR and other digital technologies..... you have BER.  That's Bit Error Rate.  The signal is good, then it gets a bit funky, then it's just gone.  The BER gets beyond what the radio can 'fix' and you get nothing after that.  Digital radios will blank out around the point that you are at the beginnings of audio quality issues with wide band analog.  So while digital will talk farther than analog on a quiet channel, a shared frequency will have less coverage due to interference from neighboring repeaters on the same frequency. 

So be careful of what you wish for. 

 

Oh, and if you think that this is going to get them to open up linking, it will do the exact opposite.  Linked repeaters don't allow you to monitor the repeater output for a repeater you are linked to.  So it could be creating interference at the other end that you wouldn't be aware of.  But just because you aren't aware of it, doesn't mean it's not causing an issue. 

 

 

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5 hours ago, wqnd300 said:

People think Simulcasting is ok, and look what happened in NY. If you want all this extra crap just go Amateur radio.

Objection your honor, hearsay.

No one but that system's owner actually knows what happened. All we actually know is what he's told the club's president. I'm still not convinced that the 'official' story there is what's actually happened, especially given that no other linked GMRS repeater system seems to have received anything similar.

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