Foxhunt opportunity: Data transmissions on GMRS 550 and 650 in Nashua area

n1das

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I've been hearing bursts of data transmissions continuously on two of the GMRS primary channels, 462.550MHz and 462.650MHz. It sounds like somebody set up some data modems on the GMRS channels. Check out the zip file with recordings of how the raw data stream sounds.

FRS allows a few short bursts of data at a time on the original 14 FRS channels such as for transmitting GPS location data from a GPS-equipped FRS radio to other radios. The Garmin Rino radios come to mind. No data transmissions are allowed on the 8 GMRS primary channels. The revised GMRS rules effective September 2017 didn't change any of that. The major change with the new rules affecting FRS was that FRS was upgraded to accommodate the 22-channel GMRS/FRS combo bubble packs with a 2W power limit as the new FRS and will no longer be type accepted as GMRS/FRS combo radios. These radios are type accepted as FRS only. GMRS didn't change.

Frequencies: 462.550MHz, 462.650MHz. These have been confirmed on more than one receiver of different designs so I know it's not an image of something else and not due to overload / intermod from nearby transmitter sites.

462.550 area and hours of operation:
462.550 data narrowed down to along Amherst St / 101A from Exit 7W on the FEET westbound to the Thornton Rd intersection. It is strongest in the vicinity of Somerset Plaza. It goes away when more than about a half a mile from either side of Amherst St / 101A. It appears to be from one of the businesses along the strip. I have not heard it at night so far, only heard during the day. I haven't fully nailed down the hours of operation yet. My crazy work schedule right now won't allow me much time to chase it down further.

462.650 area and hours of operation: I haven't tried to find this one yet. I only hear it weakly on a handheld at home. I live up on the hill in the south end and my radio coverage favors north and west.

For anybody interested in chasing this further, have at it. I haven't been on a good foxhunt in a while.
 

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jmarcel66

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Look for areas of construction. There may be RF fed levelers or similar units on tripods and they've been on GMRS before. Had one on 462.575 for weeks in Concord.
 

bill4long

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n1das

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This company has a business-pool license for 462.650 , and is apparently the only company in the USA that does, and their field of operation is about the same distance that you are reporting, to their licensed address. Maybe they have something to do with it. Just a thought.

Interesting. There are a few grandfathered businesses still using GMRS but the first use of the freq was in 1999 according to the license. Too late to be grandfathered.
 

ecps92

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Must be a typo, as that is a ZA frequency, not an IB/IG
Interesting. There are a few grandfathered businesses still using GMRS but the first use of the freq was in 1999 according to the license. Too late to be grandfathered.
 

mmckenna

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Must be a typo, as that is a ZA frequency, not an IB/IG
I don't know, but I've seen the FCC blindly provide GMRS frequencies to ineligible users in the past, well after the GMRS rule changes. Sometimes the FCC catches it and pulls it, sometimes they don't.
 

n1das

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GARMIN has some FRS/GMRS hand-held radios that can send GPS coordinates/data to each other.

This is unlikely to be Garmin radios because transmitting GPS coordinates/data is allowed only on the original 14 FRS channels and not allowed on the GMRS primary channels. Continuous transmission of GPS coordinates/data is also not allowed. They are required to stay silent for several seconds after a data transmission. What I was hearing on 550 and 650 was transmitting continuously. The recordings I posted are 10 second long clips of what I was hearing.

My wife and I had lunch today in the neighborhood where the 462.550 source was transmitting and it was gone. I'll see if it comes back next week when people are back to work. 462.650 was still active today. I haven't narrowed down the location of the 650 source yet.
 

bill4long

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Interesting. There are a few grandfathered businesses still using GMRS but the first use of the freq was in 1999 according to the license. Too late to be grandfathered.
This isn't grandfathering. They have an active business-pool license for that frequency. Strange? Yeah. Ask the FCC why. But the fact is, it is an active business-pool license for that frequency.
 

Thunderknight

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This isn't grandfathering. They have an active business-pool license for that frequency. Strange? Yeah. Ask the FCC why. But the fact is, it is an active business-pool license for that frequency.
Grandfathering on GMRS freqs meant they could continue to have a business license and renew it, but couldn’t change station parameters. That doesn’t explain the 1999 thing though.
 

bill4long

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Grandfathering on GMRS freqs meant they could continue to have a business license and renew it, but couldn’t change station parameters. That doesn’t explain the 1999 thing though.
Whatever the case, it's a business-pool license (re)issued in 2013.
 

n1das

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Whatever the case, it's a business-pool license (re)issued in 2013.
It is a moot point because that's not at all what I'm hearing. To be hearing that IB pool licensee up here in NH on 650 would suggest wide area coverage given the transmitter power output on the license and I would expect to hear it everywhere especially when I'm down in MA and close to it. Marshfield MA is south of Boston on the coast towards the Cape. The station class is MO for mobile and what I'm hearing is stationary. From localizing the 550 source earlier this week which was gone today, the coverage footprint wasn't much beyond what you can do with a 4W UHF Part 90 portable on simplex.
 

bill4long

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It is a moot point because that's not at all what I'm hearing. To be hearing that IB pool licensee up here in NH on 650 would suggest wide area coverage given the transmitter power output on the license and I would expect to hear it everywhere especially when I'm down in MA and close to it. Marshfield MA is south of Boston on the coast towards the Cape. The station class is MO for mobile and what I'm hearing is stationary. From localizing the 550 source earlier this week which was gone today, the coverage footprint wasn't much beyond what you can do with a 4W UHF Part 90 portable on simplex.
You're prolly right. Just a thought.
 

n1das

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You're prolly right. Just a thought.
Yep, and it's an OK thought to have. The first thing we often do is check to see who is licensed on a particular freq in a given area.

I'll probably get some time to better sniff 'em out after my crazy work schedule settles down. I was able to narrow down the 550 source earlier this week because by dumb luck as usual I happened to stumble upon it in my travels.
 
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jmarcel66

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This company has a business-pool license for 462.650 , and is apparently the only company in the USA that does, and their field of operation is about the same distance that you are reporting, to their licensed address. Maybe they have something to do with it. Just a thought.

This license is a hot mess. All sorts of doesn't make sense going on. They've got 462.650 licensed IB, illegal by FCC standards themselves. They've got should be pairs that aren't paired, a couple 475Mhz frequencies w/no 472 output. All the post decimal frequencies line up if you look at it more closely, but the pairs listed don't.

I'm not sure what ICE does on UHF if anything given the size and scope of their 900Mhz Trbo system. And like David said, definitely not what's happening in Nashua.
 

ecps92

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ICE has many existing UHF [Rentals and Internal user] Pairs still in Operation outside of their DMR 900 which moved from 800 LTR

What we as Scannists or even some Radio Shops consider inputs, are regularly used as simplex channels as well.
Not as rare as one would think.


This license is a hot mess. All sorts of doesn't make sense going on. They've got 462.650 licensed IB, illegal by FCC standards themselves. They've got should be pairs that aren't paired, a couple 475Mhz frequencies w/no 472 output. All the post decimal frequencies line up if you look at it more closely, but the pairs listed don't.

I'm not sure what ICE does on UHF if anything given the size and scope of their 900Mhz Trbo system. And like David said, definitely not what's happening in Nashua.
 

n1das

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Look for areas of construction. There may be RF fed levelers or similar units on tripods and they've been on GMRS before. Had one on 462.575 for weeks in Concord.
This apparently IS what I am hearing. It was active again today on 550 and I found the construction site too. It's on Amherst St / 101A eastbound next to the Eversource / PSNH building across the street from Somerset Plaza. I had my BC396xt handheld scanner with me and got Close Call hits with it on 550 as I drove by the construction site. The coverage area where I can hear it is about what you can expect with a UHF Part 90 portable on simplex. It probably transmits with a couple of Watts like a UHF Part 90 portable.

Now to sniff out the 650 source if it's still active.....

Anybody have more information on these devices?
 

ecps92

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The ones I've run across on Non GMRS Channels were similar to [all on inputs, driving repeaters BONK-ers
This apparently IS what I am hearing. It was active again today on 550 and I found the construction site too. It's on Amherst St / 101A eastbound next to the Eversource / PSNH building across the street from Somerset Plaza. I had my BC396xt handheld scanner with me and got Close Call hits with it on 550 as I drove by the construction site. The coverage area where I can hear it is about what you can expect with a UHF Part 90 portable on simplex. It probably transmits with a couple of Watts like a UHF Part 90 portable.

Now to sniff out the 650 source if it's still active.....

Anybody have more information on these devices?
 
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