Listening to one talk group on a DMR system

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sallen07

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Background: I am fully aware of the "Whistler gives us DMR for free and Uniden makes us pay for it" discussion, and I understand why that's the case and I own Uniden scanners with the paid upgrades. So please let's leave THAT debate out of this thread. I also used to have a Pro-668 with the Whistler firmware upgrade (worth every penny I spent on it). I ended up giving that scanner to my dad, and it does a great job for him on the DMR conventional frequencies the local police use.

Here's my situation. I would like to listen to *one* talk group on one of the local DMR trunked systems (SaiaNet, for those who live in Western NY). I have been using a BCD996P2 (with the DMR upgrade) to do that, but with the proliferation of DMR and NXDN in Monroe County I'd love to free that scanner up for other purposes.

So I'm looking for folks out there that are doing what I am looking to do ... listening to a single TG (or perhaps a two or three) on a DMR Motorola Connect Plus system using a Whistler scanner. How well does that work for you? Is that a viable option for me?

Thanks!
 

sallen07

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How many frequencies and how busy is the system?
Here's the system:


The Rochester site has eight frequencies which actually surprises me since I don't think it's *that* busy, although they have no doubt planned for future growth. The system is fairly new and they have definitely been adding subscribers; a bunch of school districts (specifically buses) came on-line last summr. I do find it interesting that in Monroe county there is one site but in Erie County (Buffalo) there are five sites and a total of 25 frequencies, which is probably an indication of the relative usage in the two counties.

It's hard to judge how busy the system is right now since all the schools are closed and I'm sure many of the businesses are impacted too.
 

KevinC

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Here's the system:


The Rochester site has eight frequencies which actually surprises me since I don't think it's *that* busy, although they have no doubt planned for future growth. The system is fairly new and they have definitely been adding subscribers; a bunch of school districts (specifically buses) came on-line last summr. I do find it interesting that in Monroe county there is one site but in Erie County (Buffalo) there are five sites and a total of 25 frequencies, which is probably an indication of the relative usage in the two counties.

It's hard to judge how busy the system is right now since all the schools are closed and I'm sure many of the businesses are impacted too.
Ok, the busier a system is and the more frequencies it has will increase the chances of missing your target TG. I find more than 8 or so frequencies really hampers trying to follow a single TG, but your mileage may vary.
 

sallen07

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Ok, the busier a system is and the more frequencies it has will increase the chances of missing your target TG. I find more than 8 or so frequencies really hampers trying to follow a single TG, but your mileage may vary.
I forgot to mention (but maybe this was obvious) that my plan was to *not* have a wildcard TG, and to lock out all the other TGs from the database (or just delete them).
 

KevinC

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I forgot to mention (but maybe this was obvious) that my plan was to *not* have a wildcard TG, and to lock out all the other TGs from the database (or just delete them).
Yep, but since the Whistler doesn't use the control channel for trunk tracking it has to check each frequency for your TG and if other traffic is on those frequencies it really slows things down.
 

buddrousa

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I am not sure how long whistler looks at each frequency for info but Uniden looks 400ms so that is 1.5 seconds per 4 channels so you may be looking at something like 3 seconds to relocate your TG is Whistler uses the same timing.
 

sallen07

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I am not sure how long whistler looks at each frequency for info but Uniden looks 400ms so that is 1.5 seconds per 4 channels so you may be looking at something like 3 seconds to relocate your TG is Whistler uses the same timing.
If I understand how a Whistler scanner 'does' DMR, it would stop on a frequency if there was a DMR transmission active and then look for the TG, yes? But if there was no voice traffic on that frequency, it wouldn't break squelch, right? So it would just skip that frequency, just as if it was an analog (or P25 conventional) frequency with no current traffic?
 

KevinC

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If I understand how a Whistler scanner 'does' DMR, it would stop on a frequency if there was a DMR transmission active and then look for the TG, yes? But if there was no voice traffic on that frequency, it wouldn't break squelch, right? So it would just skip that frequency, just as if it was an analog (or P25 conventional) frequency with no current traffic?
Correct, so the busier a system is the longer it takes.
 

sallen07

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Correct, so the busier a system is the longer it takes.
So the answer is, "YMMV". :)

I knew that before I asked. I was just hoping for some validation from people who are doing something similar to justify getting another scanner. Maybe I should have posted in the NY forum to see if anyone nearby is listening to this particular system with a Whistler scanner. The truth is that I if go ahead and get the Whistler, I won't know if it does what I want until things get back to normal, which is looking to be months away. On the other hand, one cannot have too many scanners, right? Especially one that's different from anything else I have so it would be a new toy to help keep me entertained in the meantime?
 

jonwienke

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The Uniden trunk tracking is a better method for monitoring a single talkgroup, especially on a busy system with multiple site frequencies. If you do a site hold, it parks on the control channel and doesn't scan, and you'll miss nothing on the talkgroup of interest. If you're constantly scanning voice channels, you'll miss more traffic, especially short transmissions.

But of course you have to pay for the trunk tracking license stuff.
 

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So the answer is, "YMMV". :)

I knew that before I asked. I was just hoping for some validation from people who are doing something similar to justify getting another scanner. Maybe I should have posted in the NY forum to see if anyone nearby is listening to this particular system with a Whistler scanner. The truth is that I if go ahead and get the Whistler, I won't know if it does what I want until things get back to normal, which is looking to be months away. On the other hand, one cannot have too many scanners, right? Especially one that's different from anything else I have so it would be a new toy to help keep me entertained in the meantime?
I am doing the same exact thing and as I said it depends on how busy the system is and the more frequencies it has can make it worse.
 

sallen07

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The Uniden trunk tracking is a better method for monitoring a single talkgroup, especially on a busy system with multiple site frequencies. If you do a site hold, it parks on the control channel and doesn't scan, and you'll miss nothing on the talkgroup of interest. If you're constantly scanning voice channels, you'll miss more traffic, especially short transmissions.

But of course you have to pay for the trunk tracking license stuff.
Didn't I say "let's not go there", Jon? :p

Right now I don't even have to do a site hold since there is only one site programmed. I have all TGs other than the one of interest avoided, and I'm doing an ID Scan rather than search. So my 996P2 is sitting there listening to the control channel, and if there is traffic on my one TG, I hear it.

But like I said, there are other NDXN and DMR systems in our area that I'd like to monitor ... while still not missing anything on this one TG. So I can either get another 996 and pay for the upgrades, or I can save some $ and try using a Whistler for this purpose and free up the 996.

Based on the traffic I was seeing on the system before I set things up to just listen to that one TG (and before Covid19), I think it's overbuilt for current demand, but I'm sure the SaiaNet folks hope that changes in the future.

Help me out here guys ... trying to justify a new toy! :)
 

buddrousa

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Goodluck depending on the traffic I would expect 1/2 second to 3 seconds delay. Like you I have both and only use mt TRX's until I get the system figured out.
 

sallen07

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Find a place with a 30 day return policy, try it for a few weeks and see how it works. ;)
Nah, I would just repurpose it. There are a number of conventional DMR channels around here I could use it for. Plus I probably won't know if it does what I want until at least this September since it's looking more and more like the schools around here may be done until at least then, and a lot of the traffic on the system is buses.
 
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