Baltimore County two-tone over P25?
- Thread starter ocguard
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Do they still do house sirens in Baltimore County? Many of those had tone-based controls - particularly those not mounted on station houses.
These are mostly gone!
TG 9452
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The County has been using the FSA system for several years, digitally alerting stations. In doing so, career Plectron tones going over low band were disabled, as there was no longer a need for them. This "saved time" during the dispatch of assignments. Volunteer tones are still going out over 46.46, as well as any career tone assigned to a pager (Chiefs, EMS officers, Safety, etc.) These tones are solely to alert pagers and no longer activate in house alerting or sirens, that again is done by the FSA.
In reference to the original post, it is "rumored" that P25 is being tested over the North channel. As they are still using low band, a band no longer supported by any pager manufacture, this would be an alternative to alerting those using pagers. To my knowledge, this is still in the test trial period and volunteers are still being issued Minitor pagers operating off the low band, though most use Active911 via cell phone.
For the fun of it, here are the volunteer stations still using house sirens...
Middle River 74-Essex 51 (old Hyde Park Station)-Lutherville 30- Pikesville 32 -Arbutus 35- Lansdowne 36- English Counsul 37- Long Green 38-Glyndon 40- Reisterstown 41- Upperco 85 (new station being built, unsure if it will carry over)- Hereford 44- Maryland Line 45- Jacksonville 47- Kingsville 48- Butler 49- Chestnut Ridge 50
In reference to the original post, it is "rumored" that P25 is being tested over the North channel. As they are still using low band, a band no longer supported by any pager manufacture, this would be an alternative to alerting those using pagers. To my knowledge, this is still in the test trial period and volunteers are still being issued Minitor pagers operating off the low band, though most use Active911 via cell phone.
For the fun of it, here are the volunteer stations still using house sirens...
Middle River 74-Essex 51 (old Hyde Park Station)-Lutherville 30- Pikesville 32 -Arbutus 35- Lansdowne 36- English Counsul 37- Long Green 38-Glyndon 40- Reisterstown 41- Upperco 85 (new station being built, unsure if it will carry over)- Hereford 44- Maryland Line 45- Jacksonville 47- Kingsville 48- Butler 49- Chestnut Ridge 50
Well, in the off chance anyone in Baltimore County OIT or FD sysadmins read this, the P25 paging on a Unication is working flawlessly for us. Please do not turn it off! If there is an official secret beta group currently testing this out, please send me a DM. I’ve got 3 other members in our station now using P25 paging as we conduct our own beta test. And now everyone wants a Unication. Keep up the great work this is the way to do it. A unified radio for paging and monitoring communications while enroute on calls will save lives.
I have loaned my G4 to a friend who is testing it for his company, and will be reprogramming a few other G4s privately owned by members there (used as scanners) to function as pagers.
I monitored all three battalion chief tone groups yesterday for about 16 hours and had flawless activation as well. One concern, looking at the BCoFD pager tone table, as compared to Unication's "ideal" tones for two-tone over P25 throughput, is that some are close to border of the tone range. Maybe I'll cycle through each station's tone pair and see how it goes.
I was really surprised that the fast duo-tone format timing was making the grade, since such a small snippet of the tone is audible on P25, but it's definitely working.
I think I’m using 200ms durations for short and long. I actually think this is by design - the short tones. If you think about it, P25 is digital. It is crystal clear transmission. In the days of analog with all the static and all, you needed a longer tone to make sure you vibrate the reed (so to speak - I am going way back). With digital, you just need enough tone length for the microprocessor to recognize the frequency. I don't think they simply ran a patch cable from the 46.46 transmitter to the P25 "aux in"
. I think this is a planned upgrade and clever RadioReference users found the TG and here we are as early adopters. And I think it is great that its actually happening.Funny you mention chief tones. Now that I have this working, I can get creative. I was thinking of setting up a knob for box alarms that would alert with a custom TTS such as “<beep beep> <WEST / CENTRAL / EAST> <BOX>. I would do that without voice record and pick a specific color scheme, in addition to our station fire and medic tones (which do use voice record and display red for fire alerts and blue for medic alerts). You answered my first question which was "do the chief tones work"!
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If you really get into the pre- and post- behavior, you could even tell the pager to switch scan lists based on which tone decoded. For example, west battalion tone decodes, scan Tac22. The possibilities are endless. This is def good stuff. And I was impressed at how loud and robust the alert tones are.
And don't forget the multi-alarm tones. If they're still used, they are sent for working fire dispatch and greater alarms. Not sure if they've been phased out tho. Haven't religiously listened to BCo in years.
Yes - I have thought about the 'revert' feature, but my station is on the line of Central and West. Instead, I have specific knob positions for West, Central and East. For example, Central knob position will scan central, 1-2, 6-2, as the main TGs, but also has 1-0, 1-1, 1-3, 1-4, 1-5, etc., and 6-0, 6-1, 6-2, 6-3, etc.. Sometimes they use those for water ops, etc. So this will capture divisional up and down, even for a second box in same division, and you can block out or hold on whatever you want on that knob position.
I think I’m using 200ms durations for short and long. I actually think this is by design - the short tones. If you think about it, P25 is digital. It is crystal clear transmission. In the days of analog with all the static and all, you needed a longer tone to make sure you vibrate the reed (so to speak - I am going way back). With digital, you just need enough tone length for the microprocessor to recognize the frequency. I don't think they simply ran a patch cable from the 46.46 transmitter to the P25 "aux in"
Funny you mention chief tones. Now that I have this working, I can get creative. I was thinking of setting up a knob for box alarms that would alert with a custom TTS such as “<beep beep> <WEST / CENTRAL / EAST> <BOX>. I would do that without voice record and pick a specific color scheme, in addition to our station fire and medic tones (which do use voice record and display red for fire alerts and blue for medic alerts). You answered my first question which was "do the chief tones work"!
I wonder, if you listen to the TG that's carrying the tones side-by-side with 46.46mhz, are they timed exactly the same?
I've always liked Baltimore County's paging format, as far a timing goes. The only thing I didn't like (and I didn't know I didn't like it until I ended up in another county with longer B-tones) is the short burst of alerting that you get out of a Minitor.
This is slightly ot, but I'm working on a project in the Baltimore area and I'm trying to find an efficient way to program the G5 for fire ops. I can devote one zone (8 knob positions) to the system. Currently I use one knob position to monitor the dispatch and ops tgs (the radio scans between them, prioritizing the dispatch tg.) I don't have any incident tgs programmed atm. I'm a bit confused why there are 4 ops tgs, but only 3 battalions with two incident tg sets each - can anyone add some context?
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Central-East-West for standard runs. Tac 1-2, 2-2, 3-2 (South) for tactical incidents (fires, rescues, hazmat.) Additionally, Tac 4-2, 5-2, & 6-2 for additional incidents within the battalion. Example, a central firebox would be on 1-2 but if an additional central box would to drop, it would operate on 4-2.
Does the county still use the North Ops tg (9452)?
They never did!
The "North" talk group was put into place when P25 went live and the northern part of the county was operating on a separate RFSS. The idea was, that if site trunking occurred, and the main RFSS and north RFSS became disconnected, the "NORTH" talk group would be the divisional response talk group for units in that area. Evidentially, in a Moto 7.x system, wide area talk groups must have a revert RFSS for site trunking. When the northern RFSS was absorbed into the main one, they recycled this talk group for their two-tone beta. This is also why many of the TAC talk groups were labeled N or S as they would only work on those RFSSs during site trunking.
That’s one of the bad things on the shorter tone sets for sure. My county uses the standard 1/3 and GC but even with that I set the custom timing on the pager alert to be longer than average. There’s a slight risk the longer alert steps on a dispatch but I’d take that over the shorter alerts. Especially with how deep of a sleeper I normally am.
Actually, a central firebox would be on 1-2 but if an additional central box would to drop, it would operate on 6-2. 4-2 is a second box on East; 5-2 is a second box on West.
boatbod
Member
P25 Phase 2 supports encoding of tones in special "tone" frames rather than the (far from optimal) Phase 1 method of parameterizing them using the voice encoder. The only snag with this approach (as noted by maus92) is that certain individual tone frequencies originally available to the analog pagers are insufficiently unique to be reliably used on Ph2. i.e. they sit mid-way between two tone ranges and thus cannot be guaranteed to encode properly.
The solution used for MD FiRST alerting (here in Talbot and probably elsewhere) is to assign new tone pairs to each station that are used on Ph2 for Unication G4/G5 pager activation, and retain the old tone pairs used on the VHF analog system for Minitor and Unication G1 pagers.
The solution used for MD FiRST alerting (here in Talbot and probably elsewhere) is to assign new tone pairs to each station that are used on Ph2 for Unication G4/G5 pager activation, and retain the old tone pairs used on the VHF analog system for Minitor and Unication G1 pagers.
Baltimore County also used to have more then 3 battalions. Talk about maybe adding more has happened ever since the number was reduced.
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