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Digital Signals on gmrs repeaters?


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Posted

Why do some of the gmrs repeaters get what sounds to be a digital signal transmittting from them for long periods of time. Say 5 or 10 minutes at a time. It’s an awful sound annoying as all get out. What’s with that? Id imagine it makes using the repeaters(not that I use them but very very rarely) all but impossible when it is digitally transmitting …..

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Posted

Learn to live with it. In my area there is a business operating a illegal DMR repeater and has been for a few years. It's been reported to the FCC by numerous folks, yet it's still there.

The best repeater in the area is running a Motorola Quintar repeater that can work with analog or P25 digital. The info to use P25 is on their website if you have a P25 capable radio. 95% of all traffic is analog though. I hear P25 maybe a total a 5 minutes a month. It freaks out new users and the FCC rule hounds. For such a nice FREE repeater, it's a small annoyance I can live with.

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Posted
2 minutes ago, MarkInTampa said:

Learn to live with it. In my area there is a business operating a illegal DMR repeater and has been for a few years. It's been reported to the FCC by numerous folks, yet it's still there.

The best repeater in the area is running a Motorola Quintar repeater that can work with analog or P25 digital. The info to use P25 is on their website if you have a P25 capable radio. 95% of all traffic is analog though. I hear P25 maybe a total a 5 minutes a month. It freaks out new users and the FCC rule hounds. For such a nice FREE repeater, it's a small annoyance I can live with.

And I believe that the FCC has issued some experimental waivers to some repeaters to allow them to test digital on GMRS, so we cannot immediately assume that a repeater with occasional digital users is in violation of.

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Posted
1 minute ago, SteveShannon said:

And I believe that the FCC has issued some experimental waivers to some repeaters to allow them to test digital on GMRS, so we cannot immediately assume that a repeater with occasional digital users is in violation of.

I understand that. I don't know or even care if the P25 repeater has a waiver. It's used so infrequently and if you have tone on receive you won't hear P25 at all. It doesn't bug me but like I said, some folks go banana's the when hearing it for the first time.

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Posted
50 minutes ago, MarkInTampa said:

In my area there is a business operating a illegal DMR repeater and has been for a few years. It's been reported to the FCC by numerous folks, yet it's still there.

You sure it's really operating illegally? Remember before the 2017 rule changes business could get a GMRS license. So long as the business has maintained their license, didn't let it expire, they can continue to renew it and operate LEGALLY. The only way to find out is locate the business in the FCC's database, assuming it exists, and if so is their license still active.

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Posted

 

 

30 minutes ago, Lscott said:

You sure it's really operating illegally? Remember before the 2017 rule changes business could get a GMRS license. So long as the business has maintained their license, didn't let it expire, they can continue to renew it and operate LEGALLY. The only way to find out is locate the business in the FCC's database, assuming it exists, and if so is their license 

It is not listed in the FCC database, at least by frequency. The local Motorola shop is one of those that filed a complaint. It has made .700 unusable in the area.

The City of Tampa does have a legacy license on .625 that ID's every 10 minutes but in 3 years I have yet to hear anyone use it. I have a list of all legacy licenses by zip code if anyone wants it. 

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Posted
14 minutes ago, MarkInTampa said:

 

 

It is not listed in the FCC database, at least by frequency. The local Motorola shop is one of those that filed a complaint. It has made .700 unusable in the area.

Hum.... If it's operating illegally then I suppose they really couldn't complain if it got hijacked by local GMRS users. If they did the FCC might take more of an interest in it and ask a lot of questions they would rather not answer. Their other choice is to shut it down and apply for a legitimate business frequency and move it there.

And SDR dongle with the decoding software, or one of those D878UV's using the digital monitor function, will show you all the color codes, slot numbers, talk groups and user ID's on the repeater. While the D878UV might not be that great of a radio the digital monitor feature is one of it's very useful one's for getting info on unknown DMR traffic.

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Posted
17 minutes ago, Lscott said:

Hum.... If it's operating illegally then I suppose they really couldn't complain if it got hijacked by local GMRS users. If they did the FCC might take more of an interest in it and ask a lot of questions they would rather not answer. Their other choice is to shut it down and apply for a legitimate business frequency and move it there.

And SDR dongle with the decoding software, or one of those D878UV's using the digital monitor function, will show you all the color codes, slot numbers, talk groups and user ID's on the repeater. While the D878UV might not be that great of a radio the digital monitor feature is one of it's very useful one's for getting info on unknown DMR traffic.

It's encrypted DMR. About all you can see with SDR are the headers at start of tx and they are using GPS tracking and reporting but can't see the data. It showed up 2 years or so ago and drove a really strong GMRS repeater off the frequency. A few other GMRS repeaters have tried using the frequency only to give up after a few weeks and move to another frequency.

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Posted

This all reminds me of years back there was a company that if I’m remembering correctly had communications from their tractors on farms that sent digital info back to the tractor machinery company and illegally on GMRS frequencies. The FCC did take action.

11 minutes ago, MarkInTampa said:

they are using GPS tracking and reporting but can't see the data. It showed up 2 years or so ago

I’m not saying it’s them but it was two years ago Midland got a wavier

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Posted
2 minutes ago, WRUU653 said:

This all reminds me of years back there was a company that if I’m remembering correctly had communications from their tractors on farms that sent digital info back to the tractor machinery company and illegally on GMRS frequencies. The FCC did take action.

I’m not saying it’s them but it was two years ago Midland got a wavier

Interesting.  Garmin got a waiver even before that to send location data.  Theirs is a really neat feature that works very well with their gps map also.

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Posted
4 minutes ago, WRUU653 said:

This all reminds me of years back there was a company that if I’m remembering correctly had communications from their tractors on farms that sent digital info back to the tractor machinery company and illegally on GMRS frequencies. The FCC did take action.

I’m not saying it’s them but it was two years ago Midland got a wavier

Not in this case. You can tell by the DMR headers it is running a Motorola system.

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Posted
1 hour ago, MarkInTampa said:

About all you can see with SDR are the headers at start of tx

One other course is if the repeater is located on a commercial, for rent, tower the owner of the tower may not want that repeater there if it's operating illegally.

If nothing else works then likely you may need to hijack the repeater unless it's locked down by the SU's, subscriber unit, electronic serial number or other access restriction method. It might not matter if the unauthorized traffic is encrypted or not from the hijacker. If it has to run encrypted chances are it's RC4, which is compatible with Motorola's enhanced privacy and other manufacture's 40 bit encryption. 

I have my Kenwood NX-1300's enabled for it if I really need the feature.

https://forums.mygmrs.com/gallery/image/290-nx-1300duk5/?context=new

Some of the older Motorola radios have it enabled as a freebie on the HT's.

https://forums.mygmrs.com/gallery/image/261-motorola-xpr6550jpeg/?context=new

XPR6550Features.thumb.jpg.1229c4fd8b4bf04152979e0db43acaee.jpg

The idea is to use it enough to annoy the owner(s) to shut it down and move it. If the FCC isn't interested enough to do something about it they likely won't bother the people hijacking it either. While not ethical, and not legal to use DMR by the business or hijacking users, the FCC has invited the activity by their lack of rules enforcement.

Your choices and options are rather limited.

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Posted
9 minutes ago, Lscott said:

One other course is if the repeater is located on a commercial, for rent, tower the owner of the tower may not want that repeater there if it's operating illegally.

If nothing else works then likely you may need to hijack the repeater unless it's locked down by the SU's, subscriber unit, electronic serial number or other access restriction method. It might not matter if the unauthorized traffic is encrypted or not from the hijacker. If it has to run encrypted chances are it's RC4, which is compatible with Motorola's enhanced privacy and other manufacture's 40 bit encryption. 

I have my Kenwood NX-1300's enabled for it if I really need the feature.

https://forums.mygmrs.com/gallery/image/290-nx-1300duk5/?context=new

Some of the older Motorola radios have it enabled as a freebie on the HT's.

https://forums.mygmrs.com/gallery/image/261-motorola-xpr6550jpeg/?context=new

The idea is to use it enough to annoy the owner(s) to shut it down and move it. If the FCC isn't interested enough to do something about it they likely won't bother the people hijacking it either. While not ethical, and not legal to use DMR by the business or hijacking users, the FCC has invited the activity by their lack of rules enforcement.

Your choices and options are rather limited.

I have a Connect Systems CS800D DMR mobile sitting in a box I haven't had a chance to play with that supports Motorola encryption and passive timeslot and color code monitoring. Guess I could hook it up and try and mess with them, but not worth my time. 

What is messed up is when there is a strong band opening, the Orlando 700 repeater users will complain about hearing DMR thinking it's coming from their repeater when it's coming from Tampa. The band doesn't open that strong very often though, maybe a few times a year.

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Posted
12 minutes ago, MarkInTampa said:

What is messed up is when there is a strong band opening, the Orlando 700 repeater users will complain about hearing DMR thinking it's coming from their repeater when it's coming from Tampa. The band doesn't open that strong very often though, maybe a few times a year.

Likely they would complain anyway if it was just FM and some real chatty users had the other repeater keyed up for long periods.

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Posted
22 hours ago, MarkInTampa said:

I have a list of all legacy licenses by zip code if anyone wants it. 

Just got back to my desktop from a cruise. Here's a link to legacy licenses. It lists the license holder by zip, state and city. The list is a few years old but does give you the callsign and you can use the FCC license search to see if it's still valid or expired. I keep it bookmarked just in case.
https://www.thepeters.org/grandfathered_gmrs.html 

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Posted
3 hours ago, MarkInTampa said:

Just got back to my desktop from a cruise. Here's a link to legacy licenses. It lists the license holder by zip, state and city. The list is a few years old but does give you the callsign and you can use the FCC license search to see if it's still valid or expired. I keep it bookmarked just in case.
https://www.thepeters.org/grandfathered_gmrs.html 

Ah, that's a very useful link for this! The take-a-way is there are such grandfathered GMRS business users out there.

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Posted
23 hours ago, MarkInTampa said:

I have a Connect Systems CS800D DMR mobile sitting in a box I haven't had a chance to play with that supports Motorola encryption and passive timeslot and color code monitoring. Guess I could hook it up and try and mess with them, but not worth my time. 

What is messed up is when there is a strong band opening, the Orlando 700 repeater users will complain about hearing DMR thinking it's coming from their repeater when it's coming from Tampa. The band doesn't open that strong very often though, maybe a few times a year.

CS800D claims AES256, but does not support "Enhanced Encryption" (ARC4) as used by Kenwood and Motorola. I tried to get Jerry to add it, but he said "its a ham radio, why?"

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Posted

Many many things can cause this. Might not be digital at all.  Might be some one doing it for kicks because hey dont like the repeater. Might be a cheap repeater having a melt down.    Might be other interference.  Might be aliens? Don’t know but it’s part of radio for sure.  I hear it on all gmrs and Murs frequencies at one time/place or another.  It’s not just a gmrs repeater issue.  

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