SDS100: What is best way to find a close call DMR channel on SDS100?

LZJSR

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I am going to be at an event and want to try to pick up the handheld radios on a MotoTrbo UHF system. What is the best way to set up the scanner to grab and store the nearby radio channels to try to identify what the different channels, color codes, and slots are for this system? Also trying to catch the input frequency, not just the output frequency. I may be able to get up close and personal to a radio ( I know someone who works there), so that would make it easier.

Thanks!
 

Ubbe

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What is the best way to set up the scanner to grab and store the nearby radio channels to try to identify what the different channels, color codes, and slots are for this system?
Close call needs a constant carrier, not a pulsating one from a mobile. It also needs a single frequency being active from the base station. So if one channel at the time are used you should be able to use close call.

If you know its UHF then I would suggest to do search ranges with a bad enough antenna to only pick up the local frequencies. It would be a 50/50 chance to pick up the mobiles while searching. The SDS100 do not have the best receiver and gets easily overloaded and might also receive a signal at the wrong frequency that might confuse you. SDS100 receiver test

/Ubbe
 

n1chu

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I often thought about the same. The Moto turbo UHF systems I listen to on my SDS200 are downloaded from RR and are heard with no problems. And I have a DMR Ham transceiver which is programmed with an existing “plug” offered up from a friend. That plug includes Ct. ARES, but to date, I’ve heard nothing on either radio. The Ct. ARES group uses UHF DMR and holds a check-in session every Sunday nighT. I have yet to hear anything on my SDS200 scanner but haven’t tried the Ham DMR transceiver yet. The code plug on the ham radio was created before RR started listing Ct. ARES. The SDS200 uses the RR listing. Ct. ARES piggybacked onto the state’s statewide Moto Trbo system, named “Ct. Land Mobile Radio Net” (CLMRN). I haven’t researched why I don’t receive ARES on my SDS200 but I have checked my settings and all seem to be correct (select service types, etc.).
 

natedawg1604

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Close call needs a constant carrier, not a pulsating one from a mobile. It also needs a single frequency being active from the base station. So if one channel at the time are used you should be able to use close call.

If you know its UHF then I would suggest to do search ranges with a bad enough antenna to only pick up the local frequencies. It would be a 50/50 chance to pick up the mobiles while searching. The SDS100 do not have the best receiver and gets easily overloaded and might also receive a signal at the wrong frequency that might confuse you. SDS100 receiver test

/Ubbe
Yeah I would second doing a band search over the entire UHF band, if a site frequency is fairly active you should find it even with Intermod (my biggest pet peave with the SDS). Now that I think about, it seems like I've also had trouble finding input freqs from DMR Mobiles/Portables using custom band search, not just close call. I think I'll experiment later today with a DMR ham radio in simplex.

P-25 is a different story, if I'm within a few miles of Fire or LE vehicles I somewhat regularly get close calls hits from P-25 phase I mobiles, of course on a single voice channel. Maybe it has to do with Phase 1 vs. Phase 2.
 

popnokick

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What is the best way to set up the scanner to grab and store the nearby radio channels to try to identify what the different channels, color codes, and slots are for this system?
Best way to get all that info? Use an SDR using HDSDR, SDR#, and any of the other apps that help grab that info.
 

hiegtx

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I am going to be at an event and want to try to pick up the handheld radios on a MotoTrbo UHF system. What is the best way to set up the scanner to grab and store the nearby radio channels to try to identify what the different channels, color codes, and slots are for this system? Also trying to catch the input frequency, not just the output frequency. I may be able to get up close and personal to a radio ( I know someone who works there), so that would make it easier.

Thanks!
In addition to the "close call" issues already addressed by others, I would not advise getting too 'up close and person' to the person you know there, and asking him (or her) to key up their radio for you. Get too close, and the signal strength from a close transmitter might be enough to pop the protection diode in the scanner, leading it to take a trip to Uniden for repair.
 

LZJSR

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Best way to get all that info? Use an SDR using HDSDR, SDR#, and any of the other apps that help grab that info.
Unfortunately your solution isn’t possible. I will be at a sports stadium and am trying to find the frequencies and listen in on the sideline and stadium operations (not the team intercoms which I know are encrypted and not able to be monitored).
 
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