**New Baltimore (City) System Discussion**

[bdshayne]

Originally Posted by troymail

9104 is Northeastern District
9108 is Southwestern District

I started a list on the Wiki: Baltimore City (MD) - The RadioReference Wiki

Thanks, troymail. I've added some more labels to the wiki page based on listening last night and today.

I still hear officers asking to "go to channel C". Has anyone come across these talk groups?

[ka3jjz]

For those looking to do programming, here's the db entry for the new system

Baltimore City (Project 25) Trunking System, Baltimore, Maryland - Scanner Frequencies

best regards..Mike

[ka3jjz]

and to keep the wiki and database linked together, the new city talkgroups are now here;

Baltimore City Project 25- the RR Wiki

best regards..Mike

[jdy]

I am not proficient in programing my scanners. Radio shack's instruction manual is not user friendly. Their help service is worse. I've never been happy with the "object oriented" scanner, I'm relying on my old beat up "non object orienting" scanner. Which works fine.

[Spleen]

I don't blame you....I was programming one of the new 106's for someone and realized I had to trim the TG list because the system I was putting in apparently had too many TGs for the 106 to handle, but the -96 that was being replaced had no problem fitting them all in...

Brand new scanner....who woulda thunk..?

[ocguard]

Originally Posted by troymail

Broadcast on Fire Dispatch: Keep you portable radios on at all times.... problem?

Originally Posted by don333

Troy, using the info you've provided for the 'new' PD talk groups...after looking at the 'old' system it appears that the order of the districts is the same. I'll assume that the 'C' channels will follow the same pattern. As for keeping the portables turned on, they were having problems this morning with the apparatus radios. They were all getting the message "Out of Range". I guess they're still tweaking the system. I keep saying it, but I hope there's still some improvement to be made. Waiting to hear what ocguard has to add.

I'm not at work. The only thing I can come up with is that the list of possible control channels programmed into the mobiles did not match the actual eligible control channels used by the system once all of the repeaters were switched over to the new system. This might prevent a radio from finding a control channel and cause chaos.

Originally Posted by don333

Does anyone know what the "Fireground Announce" channels are going to be used for?

Same thing they were used for on the old system. For example, FG-1 (A16) is the primary FG-1 talk group. If that incident needs to expand, they might put EMS operations on FG 1-1 (A15) which is the first expansion talk group for FG-1. They might put water supply on FG 1-2 (A14) which is the second expansion talk group for FG-1. Then, if the incident commander wants to make a transmission to all units on all related FG talk groups, he would use FG-1 ANNC (A13) which uses regrouping logic to send the call to units on FG-1, FG 1-1, and FG 1-2. If a call is made on FG-1 ANNC, and a unit on one of the subordinate talk groups responds quickly enough (while the temporary regroup logic is still in place), it will be heard on FG-1 ANNC.

Originally Posted by Spleen

I don't blame you....I was programming one of the new 106's for someone and realized I had to trim the TG list because the system I was putting in apparently had too many TGs for the 106 to handle, but the -96 that was being replaced had no problem fitting them all in...

Brand new scanner....who woulda thunk..?

I don't understand this? How many talk groups are we talking about. One V-scanner folder can hold up to 1800 DMA objects. So in theory, in you have a TSYS (1 DMA object) with 5 channels (5 DMA objects), you could still get 1,794 talk groups in the scanner (1 TSYS + 5 channels + 1,794 TGIDS = 1800 total objects).

[bdshayne]

Originally Posted by ka3jjz

and to keep the wiki and database linked together, the new city talkgroups are now here;

Baltimore City Project 25- the RR Wiki

best regards..Mike

I have completed the identification of the existing talk groups and updated the wiki page. Thank you, ka3jjz.

[ocguard]

Originally Posted by irishman75

for idiots like my self who don't completely understand the lingo...what exactly do I have to do to get my uniden 396t to get BCFD again

You need to program a new system with the same system frequencies, selecting P25 system type, and entering the new talk group IDs listed in the DB. Hopefully you're using the cable that came with your scanner, along with either the free software available from Uniden, or the premium third-party software available online at a nominal cost.

These instructions are elsewhere in this thread, as a number of people have asked.

[dcr_inc]

Matt,
Are they migrating to Linear Simulcast? Thats the latest fade in P25.. Modulation is not C4FM like standard P25, It uses a larger timing slot which drives scanners nuts.. I was on a project in Kentucy that used it.. Makes the system radios much more signal strenght tolerant..

[ocguard]

Originally Posted by dcr_inc

Matt,
Are they migrating to Linear Simulcast? Thats the latest fade in P25.. Modulation is not C4FM like standard P25, It uses a larger timing slot which drives scanners nuts.. I was on a project in Kentucy that used it.. Makes the system radios much more signal strenght tolerant..

I have no idea. This is possible. I was under the impression that linear simulcasting was focused more on covering LARGE areas (like providing mobile coverage).

What does linear do that confuses scanners but leaves subscriber units alone?

EDIT: I don't think the trouble associated with LSM are what these folks are having. They are having trouble finding signal at all. LSM gives scanners a hard time decoding the packets. If I'm reading all this LSM stuff correctly.

[troymail]

So it's been a little more than 24 hours and I really haven't seen much of an improvement in overall reception of the new system. Just like with the PG system - I have to have my radio in the "perfect spot" to get continuous decent reception and then it's still far from perfect.....(and turns my handheld radio into a fixed location base unit!).

Definitely not as strong as the old system.....still.

[don333]

Matt, 2nd alarm this AM in the 7200 block of Harford Rd. BC4 reported trouble with all of the portables. I had the same problem yesterday. Took a ride up and down Harford Rd. and after I got north of Northern Pkwy. the signal started breaking up. I'm certainly no radio tech., but I'm wondering if adjusting the antennas (not having them all directed into the city) would help? This is really getting frustrating for those of us who need and rely on our scanners for this information.....Stay safe!

[ocguard]

Antennas were not changed as far as I know. Antennas on the city system have never been directional. Closest antenna sites to the top end of Harford Road are Good Sam Hospital and Clifton Park. They had never been directional, and I don't think that changed with the switchover.

[troymail]

Those sites were mentioned yesterday during the 0500 hour prep work by the techs --

I just don't think they are transmitting at the same power level as they did in the past.

[SkyPager]

I was working with the folks in Prince William Co last week. They told me that the FCC has changed the rules for system coverage. They were required to orient their TX antennas "into" or directed to the coverage area. They were no longer able to transmit omni from all of the sites. The still have omni RX antenna at the top of the tower.

Having said that; there are always exceptions and grandfather clauses for FCC rules. They told me that Fairfax Co was grandfathered for omni TX. If any of these TX antenna rule changes apply to Baltimore City and will apply to other jurisdictions I have no idea. Perhaps someone that has a reliable POC in the city radio shop can enlighten us.

[troymail]

Originally Posted by SkyPager

I was working with the folks in Prince William Co last week. They told me that the FCC has changed the rules for system coverage. They were required to orient their TX antennas "into" or directed to the coverage area. They were no longer able to transmit omni from all of the sites. The still have omni RX antenna at the top of the tower.

Having said that; there are always exceptions and grandfather clauses for FCC rules. They told me that Fairfax Co was grandfathered for omni TX. If any of these TX antenna rule changes apply to Baltimore City and will apply to other jurisdictions I have no idea. Perhaps someone that has a reliable POC in the city radio shop can enlighten us.

This really makes alot of sense and explains things considering what I'd been seeing for PG and now seeing for BCity.

Seems like the scanners are getting "lucky" once in a while catching the CC but it's really inconsistent. Even when it locks, the voice channel fades in and out.

[baloo]

Originally Posted by SkyPager

I was working with the folks in Prince William Co last week. They told me that the FCC has changed the rules for system coverage. They were required to orient their TX antennas "into" or directed to the coverage area. They were no longer able to transmit omni from all of the sites. The still have omni RX antenna at the top of the tower.

I can understand this for areas outside of the city, but why am I having so much trouble in the city (Hampden) with a rooftop antenna?

Does anyone know if a week digital signal sounds squeally (I don't know how else to describe it) like frequency shifts before it drops out? Maybe I'm having some other problem, but it did start with the fire transition and now on the police side.

[Spleen]

Dunno. It was a while back, using WIN500 and RR, I don't remember the details...an error message popped up and wouldn't let me dump ALL the TGs....

I don't understand this? How many talk groups are we talking about. One V-scanner folder can hold up to 1800 DMA objects. So in theory, in you have a TSYS (1 DMA object) with 5 channels (5 DMA objects), you could still get 1,794 talk groups in the scanner (1 TSYS + 5 channels + 1,794 TGIDS = 1800 total objects)

[ocguard]

Originally Posted by SkyPager

I was working with the folks in Prince William Co last week. They told me that the FCC has changed the rules for system coverage. They were required to orient their TX antennas "into" or directed to the coverage area. They were no longer able to transmit omni from all of the sites. The still have omni RX antenna at the top of the tower.

Having said that; there are always exceptions and grandfather clauses for FCC rules. They told me that Fairfax Co was grandfathered for omni TX. If any of these TX antenna rule changes apply to Baltimore City and will apply to other jurisdictions I have no idea. Perhaps someone that has a reliable POC in the city radio shop can enlighten us.

This works well when engineering a new system, because you can put the "perimeter" antenna sites very close to the edge and aim the signal into the coverage, and the "inner" antenna sites can be situated far enough within the perimeter to make sure the omni signal ends close to the edge of the coverage area.

But our system (Baltimore City) is already engineered, the the perimeter sites sit too far from the edge of the coverage area to be able to aim the signal inward and still cover the areas between the site and the edge of the city. For instance, Good Samaritan Hospital is at the top of the city along Loch Raven Blvd, but there are still a few miles between the antennas and the city limits, including MANY brick homes and a few mid rise apartment buildings.

This is why I would have LOVED to seen Baltimore City and Baltimore County integrate/network their systems, where, if a city unit ventured into the county, or was in an area where a county tower covers better that a city tower, the radio would roam to their system and continue to operate on the city talk group. This would work WONDERFULLY for the city and the county, since the county surround the city by about 90%.

I'll pay close attention as I go back to work tomorrow, but unfortunately, it's hard for me to evaluate signals since our nearest antenna site can be seen from nearly every window in the firehouse. Well, actually, I guess it's more fortunate than not -- at least I can be confident my radio will work!

[troymail]

Originally Posted by baloo

Does anyone know if a week digital signal sounds squeally (I don't know how else to describe it) like frequency shifts before it drops out? Maybe I'm having some other problem, but it did start with the fire transition and now on the police side.

Is it possible you're hearing the difference between a 3600 and 9600 control channel? They certainly sound different.