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GMRS repeaters and LMR


smalpierre

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I was scanning today, and heard some traffic on GMRS 21 (462.700) - and it was definitely on a repeater based on me being inside a concrete block house on an HT, and at least some of them from the conversations sounded like they were also on HTs - and the courtesy beeps which were identical between everyone in the conversation. Also they were at least 12 miles away.

That frequency isn't one of the "color dot" shared channels, but I'm wondering if it's possible that it's an old assigned LMR pair? One thing that leads me to believe "not LMR" is that business band was narrowbanded, and it didn't sound like it was narrow band - their voices weren't quiet, they were loud and clear.

Is there a way to find out if it is an LMR assigned pair?

 

edit: I'm aware that a business can use FRS, but is it legal for them to use GMRS for business use? Particularly GMRS repeater frequencies? Is it even possible for it to be a grandfathered LMR repeater pair?

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So far I haven't heard an ID of any sort. I was waiting for a cw id, but there was none. Listened to it for almost 2 hours while they chit chated.

I had a simular incident in Stafford NJ with Monoc ambulance bleeding over onto Ch 21 if you were 5 miles or less from the hospital. At the time monoc was using 463xxxx (I dont remember the exact number) Two things can cause this issue. 1 would be the extra high 200W output from their repeater to cover the southern end of the county as well as Burlington and Atlantic county's. This overdrives the front end of a near by UHF radio using a frequency close to the one the transmitter is on. The other would be frequency deviation where the transmitter begins to transmit off frequency enough to bleed onto other frequency's.

 

Most likely its a GMRS repeater that users are not using their calls on. Without being able to hear the traffic and knowing the area and whats around, kinda hard to speculate who is using it.

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edit: I'm aware that a business can use FRS, but is it legal for them to use GMRS for business use? Particularly GMRS repeater frequencies? Is it even possible for it to be a grandfathered LMR repeater pair?

I've experienced the same thing. A local mall 4.7 miles line of sight from my house is apparently using GMRS repeater channel 16. The same channel as the repeater I use along with nearly 30 others. The repeater seems to be used by the "housekeeping" staff and uses a different PL tone from the one the local GMRS community uses. After weeks, hours at a time mainly in the evening, I've never heard anybody ID nor does the repeater ID. As suggested it might be an old grandfathered system but somehow I seriously doubt it.

 

I know where the repeater is located due to a topic mentioned on the Mall's security frequency. Then a couple of seconds later I heard the exact same person calling the Mall's housekeeping staff on the GMRS repeater about the same issue. The security staff use Motorola radios, been there enough times and watched them. At this point I don't know if the "dispatch office", AKA security, has two radios, one for their use and the other for housekeeping or more likely one radio with both frequencies programmed in to them.

 

So far I don't know what kind of radio is used by the Mall's housekeeping staff. Since its repeater capable it likely either a GMRS radio or a commercial radio programmed with GMRS frequencies setup for repeater operation. Of course somebody could have programmed some CCR's to save money and used them.

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The wording I have seen from the FCC doesn't prohibit business use - but it does say something about "Coordinating Licensee's activities". I've seen plenty of Family Farms using GMRS.

 

A Mall that's using a non-identified Repeater on GMRS frequencies is probably NOT a "grandfathered" activity. From what I recall, those entities that received GMRS authorizations back in the day were things like AAA traffic assistance, REACT groups, and Town Watch organizations. Have you done a search of the FCC's website in your local area for that Frequency? If they're legit, you should find a license on the frequency, even if it's held in some other entity's name (Like an operating company for the Mall).

 

In your particular scenario, I'd be tempted to put one of my repeaters on the 462.xxx output frequency and match their PL/DPL. Then I'd start ID'ing with Morse Code every 15 minutes (with PL!)  If they're a legit user, you should get a phone call pretty quickly. If they're not legit, they'll go away soon enough. Hopefully they would get a real License on an IG business band frequency....  but there's probably a reason they didn't do that to start with.

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The wording I have seen from the FCC doesn't prohibit business use - but it does say something about "Coordinating Licensee's activities". I've seen plenty of Family Farms using GMRS.

 

A Mall that's using a non-identified Repeater on GMRS frequencies is probably NOT a "grandfathered" activity. From what I recall, those entities that received GMRS authorizations back in the day were things like AAA traffic assistance, REACT groups, and Town Watch organizations. Have you done a search of the FCC's website in your local area for that Frequency? If they're legit, you should find a license on the frequency, even if it's held in some other entity's name (Like an operating company for the Mall).

 

In your particular scenario, I'd be tempted to put one of my repeaters on the 462.xxx output frequency and match their PL/DPL. Then I'd start ID'ing with Morse Code every 15 minutes (with PL!)  If they're a legit user, you should get a phone call pretty quickly. If they're not legit, they'll go away soon enough. Hopefully they would get a real License on an IG business band frequency....  but there's probably a reason they didn't do that to start with.

 

I'm not 100% sure how I can get their PL. I rolled through every CTCSS tone and keyed up, no repsonse, no squelch tail - so I'm assuminng they're using DCS. There's over 100 of those to roll through - I'll do it when I have time. My understanding is that most repeaters don't retransmit the tone unless the're using an input and privacy tone - but I guess it's possible? Most of the repeaters I see that do that use the same tone for both, so it's worth a shot.

 

I'm not sure where to look on the FCC website, I'm looking but not finding yet - if you have a link that'd be awesome!

 

That's not a bad idea, I just wonder if their organization is small enough where the users would just wonder "what's that noise?" and brush it off. I'll probably key up, voice ID and ask them once I find the tone in.

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Start with a search on the license type specifying your state, county. If it's not there, try looking for the frequency using a B/ILT license type. If you don't find it there, contact the FCC and file an interference complaint from an unlicensed station and give them all the details you can.

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Start with a search on the license type specifying your state, county. If it's not there, try looking for the frequency using a B/ILT license type. If you don't find it there, contact the FCC and file an interference complaint from an unlicensed station and give them all the details you can.

 

 

https://wireless2.fcc.gov/UlsApp/UlsSearch/searchGeographic.jsp

 

Here? I don't see where to input license type. Also not sure which frequency to enter - the frequency the radios listen to, the repeater input, or what? I'd assume what the repeater is transmitting on so 462.700 ,, 

 

Anyway - I came up with nothing there - checked the box for "mobile area of operations" and the "nationwide" and "continental" boxes. Nothing whatsoever. Even checked adjacent counties just to be sure.

 

I don't really want to file an interference complaint right off the bat - I'm gonna try to get their PL and see what that turns up. If it's just a couple of guys using a repeater with permission and everything it's not really interfering with me. If they're using someones repeater without permission, it's the repeater owners call. If they've just set up a repeater on top of a high rise they're working on and it's unlicensed commercial, AND they act like jerks about it ... well then I'll get with the FCC.

 

I really do want to be nice, until it's time not to be nice!

 

 

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Found them! I feel dumb - it's on this site :D I really thought I checked that!

They're not id'ing, using ani and a roger beep - and it sounded like commercial traffic, but it's not. I heard them today and it's definitely not commercial use.  They did link at least two repeaters in the same area, so I can hear them on 4 channels at once. Kind of irritating and inconsiderate, but whatever! Sounds like they're going for something in the 800mhz range soon anyway.

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I'm not 100% sure how I can get their PL. I rolled through every CTCSS tone and keyed up, no repsonse, no squelch tail - so I'm assuminng they're using DCS. There's over 100 of those to roll through - I'll do it when I have time. My understanding is that most repeaters don't retransmit the tone unless the're using an input and privacy tone - but I guess it's possible? Most of the repeaters I see that do that use the same tone for both, so it's worth a shot.

 

I'm not sure where to look on the FCC website, I'm looking but not finding yet - if you have a link that'd be awesome!

 

That's not a bad idea, I just wonder if their organization is small enough where the users would just wonder "what's that noise?" and brush it off. I'll probably key up, voice ID and ask them once I find the tone in.

Well I haven’t been that motivated to dig around in the FCC database looking for a possible grandfathered license holder for those frequencies yet.

 

Your idea of putting another repeater on the same frequency with the same PL tone I’m sure would annoy them. So would simply high jacking it, after all it is on a legal GMRS repeater channel. If the user/owner doesn’t want anybody else on their machine they can contact all parties and inform them as such. When that happens the question becomes under whose operating authority, FCC license holder, can deny general public access. Of course if the repeater is illegally operating most likely it will simply shut down or move to a business frequency. 

 

I was walking around the mall tonight just for some exercise and noticed an HT sitting on top of the push trollies used by the housekeeping staff as I walked by. It looked like your typical basic black commercial Motorola radio. So they are not using some COTS GMRS radios. Those Motorola’s had to be specifically programmed for the frequencies used.

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Just go talk to the mall management and help them fix this problem that his radio vendor needs to fix this so he does not get a fined.  If I was a legit communication shop would fix it at no change if I s????up and mislead them.  Be the hero, you may get free VIP parking for life. joking

Jack 

Well I haven’t been that motivated to dig around in the FCC database looking for a possible grandfathered license holder for those frequencies yet.

 

Your idea of putting another repeater on the same frequency with the same PL tone I’m sure would annoy them. So would simply high jacking it, after all it is on a legal GMRS repeater channel. If the user/owner doesn’t want anybody else on their machine they can contact all parties and inform them as such. When that happens the question becomes under whose operating authority, FCC license holder, can deny general public access. Of course if the repeater is illegally operating most likely it will simply shut down or move to a business frequency. 
 

I was walking around the mall tonight just for some exercise and noticed an HT sitting on top of the push trollies used by the housekeeping staff as I walked by. It looked like your typical basic black commercial Motorola radio. So they are not using some COTS GMRS radios. Those Motorola’s had to be specifically programmed for the frequencies used.

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Just go talk to the mall management and help them fix this problem that his radio vendor needs to fix this so he does not get a fined.  If I was a legit communication shop would fix it at no change if I s????up and mislead them.  Be the hero, you may get free VIP parking for life. joking

Jack 

Interesting suggestion. 

 

I’ve talked to the admin for the repeater our local group uses. Yeah, he has heard the occasional chatter too but had no idea where it originated from. Now he knows.

 

So far there really hasn’t been any co-channel interference to speak of. I’m not interested, and doubt anybody else is, being the “radio cop”. So until there is a problem will likely leave things as is. At least now IF a problem arises the admin has a good idea where to look. 

 

Anyway between the mall security and housekeeping monitoring their communications prove entertaining at times. When the weather is very cold, crummy out, bored or between normal gym visits I go to the mall and walk for an hour or two with the UHF radio inside the coat and a small D-Ring ear phone with a PTT lapel mic. I don’t want to make it obvious what I’m doing. It’s a large mall with two levels where you frequently see a significant number of people doing the same thing. If something is going on out of the ordinary I head that way to check it out.

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You go "Radio Cop" walking around undercover.  You are having way to much fun plus exercising and spying...  Invite your group to come to the Mall for fun while staying in shape in the winter.  BYOR (bring your own radio) with raincoat, hat, sunglass etc. 

Jack

Interesting suggestion. 
 

I’ve talked to the admin for the repeater our local group uses. Yeah, he has heard the occasional chatter too but had no idea where it originated from. Now he knows.

 

So far there really hasn’t been any co-channel interference to speak of. I’m not interested, and doubt anybody else is, being the “radio cop”. So until there is a problem will likely leave things as is. At least now IF a problem arises the admin has a good idea where to look. 
 

Anyway between the mall security and housekeeping monitoring their communications prove entertaining at times. When the weather is very cold, crummy out, bored or between normal gym visits I go to the mall and walk for an hour or two with the UHF radio inside the coat and a small D-Ring ear phone with a PTT lapel mic. I don’t want to make it obvious what I’m doing. It’s a large mall with two levels where you frequently see a significant number of people doing the same thing. If something is going on out of the ordinary I head that way to check it out.

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You go "Radio Cop" walking around undercover.  You are having way to much fun plus exercising and spying...  Invite your group to come to the Mall for fun while staying in shape in the winter.  BYOR (bring your own radio) with raincoat, hat, sunglass etc. 

Jack

I've done the same thing a few times at another mall close to where I lived before I moved a few years ago. I heard all sorts of crap there from hookers hanging out by the coffee shop inside, one guy brought his gun in once, fights in the food court, mall security kicked out a guy driving through the lot with a license plate scanner looking for cars on a list to repo, a couple doing their "thing" in the back seat etc.

 

I monitor that mall typically all day at work. I have the radio setup on top of the computer with a coax running to a simple 1/4 ground plane built out of a BNC PCB socket and some stiff bus wire. That's on top of my bookcase, better range and the rubber duck antennas the radios come with normally are poor performers. At least that's one thing those CCR's are good for, they make decent super cheap scanners if what you are monitoring is fairly close. Scan speed sucks, but I'm not scanning that many frequencies anyway so it's not too bad. I already had to replaced the battery pack on it because I cycled it to death using the radio 5 days a week scanning. The radio by the way is a BTECH tribander HT.

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I've done the same thing a few times at another mall close to where I lived before I moved a few years ago. I heard all sorts of crap there from hookers hanging out by the coffee shop inside, one guy brought his gun in once, fights in the food court, mall security kicked out a guy driving through the lot with a license plate scanner looking for cars on a list to repo, a couple doing their "thing" in the back seat etc.

 

I monitor that mall typically all day at work. I have the radio setup on top of the computer with a coax running to a simple 1/4 ground plane built out of a BNC PCB socket and some stiff bus wire. That's on top of my bookcase, better range and the rubber duck antennas the radios come with normally are poor performers. At least that's one thing those CCR's are good for, they make decent super cheap scanners if what you are monitoring is fairly close. Scan speed sucks, but I'm not scanning that many frequencies anyway so it's not too bad. I already had to replaced the battery pack on it because I cycled it to death using the radio 5 days a week scanning. The radio by the way is a BTECH tribander HT.

A used name brand handheld scanner from eBay beats a BTECH HT anyday at the same price.  (I have both)

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