Lscott Posted March 22 Report Posted March 22 10 minutes ago, SignallyCurious2 said: SOCWA with the water tower called back, it is not them but they’re also interested and going to help out. That’s how the transmissions are for me too, most of them data, very very few actual calls more than 1.2 sec. Latest call so far was 4:45pm. They have no idea whose antennas are on THEIR tower! The repeater is likely in the small block house at ground level. Maybe if you could gain access to the inside you might find some contact info on the equipment. That would save you a lot of research. Quote
Lscott Posted March 22 Report Posted March 22 3 minutes ago, markskjerve said: If I had to guess they are running MotoTrbo GPS tracking on the radios. The GPS system can be programmed to poll the radios every 10 minutes or every 1 kilometer of movement. They are short bursts, around 600ms to 1 second. If a car is moving it sends a lot more traffic than if it doesn't. Now that would start to make a lot more sense. Quote
Lscott Posted March 22 Report Posted March 22 Yeah, there is specific software for that sort of thing, CAD-AVL, Computer Aided Dispatch - Automatic Vehicle Location, applications. Acom Automax CAD.pdf Kenwood_KGP-2A_KGP-2B.pdf Quote
SignallyCurious2 Posted March 22 Report Posted March 22 12 minutes ago, Lscott said: They have no idea whose antennas are on THEIR tower! The repeater is likely in the small block house at ground level. Maybe if you could gain access to the inside you might find some contact info on the equipment. That would save you a lot of research. He said whatever this is, is not on their tower. He was very nice and knowledgeable, they only have 900mhz systems. Quote
Lscott Posted March 22 Report Posted March 22 1 minute ago, SignallyCurious2 said: He said whatever this is, is not on their tower. He was very nice and knowledgeable, they only have 900mhz systems. It looks like there are some cell phone slot antennas up there in the photo. I doubt those are 900MHz. I wouldn't trust their response just yet. Quote
SignallyCurious2 Posted March 22 Report Posted March 22 Just now, Lscott said: It looks like there are some cell phone slot antennas up there in the photo. I doubt those are 900MHz. I wouldn't trust their response just yet. I have no reason not to believe them, I can’t confirm that it is the water tower, only that it makes the most sense. There are other antennas in the area but he also said they operate 24/7 anyhow so the 7 am - 4:45 pm M-F doesn’t fit the bill. This leads me to believe it’s some locals that started their own network with a repeater and amp from banggood or alibaba and don’t care what they’re doing. Hard to say at this point. Quote
SignallyCurious2 Posted March 22 Report Posted March 22 1 hour ago, Lscott said: It looks like there are some cell phone slot antennas up there in the photo. I doubt those are 900MHz. I wouldn't trust their response just yet. What about Servicar? https://maps.app.goo.gl/V5WBdhAGx51DD5436?g_st=ic Quote
MarkInTampa Posted March 22 Report Posted March 22 13 minutes ago, SignallyCurious2 said: What about Servicar? https://maps.app.goo.gl/V5WBdhAGx51DD5436?g_st=ic Or Consumers Energy - tower is less than 1000ft away. Here's a Goggle street view of the tower from Nov 2021 - See if you see any shiny new antenna's. Quote
SignallyCurious2 Posted March 22 Report Posted March 22 3 minutes ago, markskjerve said: Or Consumers Energy - tower is less than 1000ft away. Here's a Goggle street view of the tower from Nov 2021 - See if you see any shiny new antenna's. Consumers is on P25 and I already spoke to their communications director on Wednesday, confirmed it is not them. I have basically called every antenna it could be with the exception of comcast, Verizon and legacy data center on delemere just north of 14. this weekend we’re going to drive around and take note of any suspected antennas in the search area to follow up Monday when the signal comes back. Quote
SignallyCurious2 Posted March 22 Report Posted March 22 Here is the antenna on servicar building, they have antennas on all of their busses too, couldn’t find much online for them but didn’t dig too deep, either. Quote
MarkInTampa Posted March 22 Report Posted March 22 6 minutes ago, SignallyCurious2 said: Here is the antenna on servicar building, they have antennas on all of their busses too, couldn’t find much online for them but didn’t dig too deep, either. From ServiCar's website: RADIO COMMUNICATIONS - All of our School Buses are equipped with two-way radio communications with our dispatch center. Our system works off of three separate repeater stations on our private 900 MHz frequency through-out the Metro-Detroit area, providing us with communications through-out and beyond the tri-county area. They are also equipped with direct talk around for trips outside of the coverage area where communications between buses is needed. Quote
SignallyCurious2 Posted March 22 Report Posted March 22 23 minutes ago, markskjerve said: From ServiCar's website: RADIO COMMUNICATIONS - All of our School Buses are equipped with two-way radio communications with our dispatch center. Our system works off of three separate repeater stations on our private 900 MHz frequency through-out the Metro-Detroit area, providing us with communications through-out and beyond the tri-county area. They are also equipped with direct talk around for trips outside of the coverage area where communications between buses is needed. Another one checked off the list! Quote
SignallyCurious2 Posted March 23 Report Posted March 23 24 minutes ago, Lscott said: The mystery continues. This is the next step - readily available SteveShannon and WRUU653 2 Quote
SignallyCurious2 Posted March 23 Report Posted March 23 Two separate antennas next door to eachother at 2425 Cole st Birmingham Michigan - landscape supply company and a tow company. Quote
SteveShannon Posted March 23 Report Posted March 23 57 minutes ago, SignallyCurious2 said: Two separate antennas next door to eachother at 2425 Cole st Birmingham Michigan - landscape supply company and a tow company. I bet the utility company loves having that tower and antenna that close to their transmission line! Quote
Lscott Posted March 23 Report Posted March 23 3 hours ago, SignallyCurious2 said: This is the next step - readily available That’s a Doppler direction finding setup. You see about the same thing on cop cars, Lojack system I believe it’s called. Quote
SignallyCurious2 Posted March 23 Report Posted March 23 9 hours ago, Lscott said: That’s a Doppler direction finding setup. You see about the same thing on cop cars, Lojack system I believe it’s called. https://www.crowdsupply.com/krakenrf/krakensdr it’s a full plug and play kit that works out of the box Quote
SignallyCurious2 Posted March 23 Report Posted March 23 It’s is a moto trbo NXDN trunking system operating in dual capacity direct mode, and contrary to what I thought, there is activity today. Radioguy7268 1 Quote
Lscott Posted March 23 Report Posted March 23 1 hour ago, SignallyCurious2 said: It’s is a moto trbo NXDN trunking system operating in dual capacity direct mode, and contrary to what I thought, there is activity today. NXDN is FDMA only. There is no TDMA mode, so it can’t be DCDM. The later is for DMR only. Motorola doesn’t sell any NXDN equipment I’m aware of. Now if it’s really TDMA it could be a P25 Phase 2 trunking system. So far TDMA mode is only used with P25 on trunking systems, not used for simplex as far as I know. Quote
SignallyCurious2 Posted March 23 Report Posted March 23 13 minutes ago, Lscott said: NXDN is FDMA only. There is no TDMA mode, so it can’t be DCDM. The later is for DMR only. Motorola doesn’t sell any NXDN equipment I’m aware of. Now if it’s really TDMA it could be a P25 Phase 2 trunking system. So far TDMA mode is only used with P25 on trunking systems, not used for simplex as far as I know. Interesting. Some guys on radio reference captured the signal and confirmed it was nxdn - and the decoder I’m using is DMR and not P25, like I said - I’m getting a ton of decoded data and it’s not the same data streams as the P25 phase 1 or phase 2. I just paid for dsd+ fast lane, waiting to get the download link now. They have some more specialty decoders another thing to note is there is a channel marker that aligns with a NXDN48 trunked system, it’s there all day / all night. Quote
Lscott Posted March 23 Report Posted March 23 3 hours ago, SignallyCurious2 said: another thing to note is there is a channel marker that aligns with a NXDN48 trunked system, it’s there all day / all night. That’s the very narrow mode of NXDN. The bandwidth is only 6.25KHz. Quote
SignallyCurious2 Posted March 24 Report Posted March 24 14 hours ago, Lscott said: That’s the very narrow mode of NXDN. The bandwidth is only 6.25KHz. Once the DSD+ fast lane people email me the download link we finna have some answers, they’ve got really good decoders. Quote
MarkInTampa Posted March 24 Report Posted March 24 On 3/22/2024 at 2:44 PM, SignallyCurious2 said: I had the best luck at 462.53188 as a “center” You show the center as 462.53188, that a whole lot closer to the standard FCC spacing of 462.53125 than 462.5325. Close enough for margin of error on most radios. I know you talked to Deltacom who has a repeater less than 7 miles away on 462.53125, running trucked radios (probably Motorola's) and they said it wasn't them but what's the hurt in confirming it? They might have a lobe of the antenna pointing line of site that is bouncing off big metal object such as the water tower. You know what the traffic looks like, try parking under their tower confirm it is not them. Lscott 1 Quote
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