**New Baltimore (City) System Discussion**

[ocguard]

Greetings!! Like most I have been tweeking settings in my PSR-500. Nothing major to report as yet. Two observations. The PSR-500 & others supports various band-plans; In WIN-500 this is listed under trunking tables.

Second the threshold HI and LO settings. According to the wiki these control how the scanner detects the CCH. I am going to experiment with lowering these values to 75 and 30. Hopefully this will allow the PSR-500 to lock onto a CC and stay there.

Refer to the Word document for screen caps.

Also, as far as I know, there would be no reason to adjust the band plan tables. The system uses standard band plans, as well as offsets, etc. SO unless I'm missing something, changing these will have NO effect on your ability to receive the system. It may actually prevent it.

Long and short, upgraded system re-engineered to minimize signal from escaping intended coverage area. Also, new simulcast method wreaks havoc on scanners. Probably nothing one can do short of buying an XTS2500 or better.

 

[SkyPager]

the idea here is to present ideas for improving reception, for those that cannot afford your XTS.
I never said these would work.

 

[ocguard]

the idea here is to present ideas for improving reception, for those that cannot afford your XTS.
I never said these would work.

I understand the concept, and I can also not afford an XTS. But what I'm telling you is, the adjustments you're suggesting/experimenting with are not pertinent to the Baltimore City radio system.

1. The Hi/Lo threshold adjustment is for use in a multi-site radio system, where each site uses different frequency pairs. It tells the scanner when to accept a site's reception level, and when to look for a better received site. Baltimore City's system sites are simulcast (all use the same frequency pairs), so this setting is contraindicated. In fact, having the multi-site setting enabled will cause the scanner to leave the CC and look for others (which is will never find because there is only one).

2. The band plan custom table settings are for systems using non-standard band plan tables, such as splinter systems, rebanded systems, non-800mhz systems, etc. Baltimore City uses the standard 800mhz band plan. So again, adjusting this setting will adversely affect your scanner's ability to monitor the system.

I appreciate that you are attempting to find tweaked settings in your scanner to optimize it's performance. But what I'm telling you is, the setting you're adjusting WILL NOT help, and may HURT your scanner's performance. The only scanner settings to adjust regarding system reception and decoding quality are attenuators and P25 decode thesholds (for Uniden users). Any other settings are unrelated.

 

[SkyPager]

We will have to agree to disagree on some of this. I asked GRE what the difference between P25 800 MHz and 800 MHz standard Tables were. This is their response; perhaps it will help those that have better signal than I have to decode more reliably.

----------------- paste ---------
P25 systems and Motorola systems are two totally different system types. While the concept is very similar between them, the channel plans are very different in how they are used.

If you are attempting to listen to a P25 system (a P25 system has a 9600bps control channel data stream), I would suggest using the P25 Auto system type setting. On most P25 systems, the trunking tables are transmitted on the control channel data stream. The scanner will automatically pick up these tables and use them without any user intervention.

In some cases, P25 systems do not transmit the band plan table information. In this case, the system would need to be set to P25 Manual and the tables would have to be determined and entered manually. In this case, the "standard" 800 MHz tables may be used, or custom tables may be entered. Which one you use depends on the system. The first set of tables you posted (P25 800 MHz) would be the Standard 800 MHz band plan for P25 9600 bps systems.

The second set of tables you posted (800 MHz standard) are for Motorola 3600bps control channels. In that case, you can use the "standard" tables, "Splinter" tables, or Custom tables (typically used for rebanded systems). The Splinter system only applies to Motorola 3600bps control channels. It is not used on true P25 9600 cc systems.

---------------- end ------------------

The tables referred to in bold print, can be seen in WIN 500 trunk tables selection.
Does anyone know if the City system transmits the trunking tables on it's CCH?

 

[ocguard]

Does anyone know if the City system transmits the trunking tables on it's CCH?

Yes, it does. Otherwise, no one would have been able to track the system using the "auto" setting.

If you want to know what the band plan is, I'll run CCDump tomorrow, screen shot it for you, and attach it to a post.

The trunking tables/band plan issue is a go/no-go issue. If you have it right, you will decode the system. If you don't have it, you'll get nothing. Again, these settings are not useful for "tweaking" reception.

 

[Dewey]

Yes, it does. Otherwise, no one would have been able to track the system using the "auto" setting.

If you want to know what the band plan is, I'll run CCDump tomorrow, screen shot it for you, and attach it to a post.

The trunking tables/band plan issue is a go/no-go issue. If you have it right, you will decode the system. If you don't have it, you'll get nothing. Again, these settings are not useful for "tweaking" reception.

Not exactly... granted a true P25 system should be the norm concerning tables and band plan, BUT... if it's not, you can have some of the problems described here, specifically, long periods of silence while holding on a single talkgroup.

I know it's not apples/apples since DC's 603d system is not P25, but when DC PD added the second custom table to the UHF side of their system, a lot of folks didn't notice since they were scanning and not holding. It took watching the system activity in something like Trunk88 or Unitrunker to see that comms were actually being missed, and why. This was because the newly added table only added one frequency, but that frequency was the lowest frequency, and therefore, an almost always active frequency (the system would use the frequencies in a lowest to highest order).

So, reeling this back in to this thread, IF B-more is doing something "different" with their table or band plan, it could be the cause of the problems people here are seeing.

Dewey

 

[ocguard]

Not exactly... granted a true P25 system should be the norm concerning tables and band plan, BUT... if it's not, you can have some of the problems described here, specifically, long periods of silence while holding on a single talkgroup.

I know it's not apples/apples since DC's 603d system is not P25, but when DC PD added the second custom table to the UHF side of their system, a lot of folks didn't notice since they were scanning and not holding. It took watching the system activity in something like Trunk88 or Unitrunker to see that comms were actually being missed, and why. This was because the newly added table only added one frequency, but that frequency was the lowest frequency, and therefore, an almost always active frequency (the system would use the frequencies in a lowest to highest order).

So, reeling this back in to this thread, IF B-more is doing something "different" with their table or band plan, it could be the cause of the problems people here are seeing.

Dewey

As far as I've read, there have been no reports of held talk groups being silent, or particular transmissions within a conversation being missed, and other troubles consistent with system tracking. From everything I've read, it's a straight reception problem leading to a decoding problem, such as a signal "fade" in the middle of the transmission. I, personally, have had no trouble "tracking" the system when it's in range, only some problems actually receiving the system in locations where it used to work. This is consistent with what I've read, too.

The table/band plan information is transmitted thru the CC. Hopefully tomorrow, I'll have time to decode it again and will post it here.

 

[SkyPager]

"The trunking tables/band plan issue is a go/no-go issue. If you have it right, you will decode the system. If you don't have it, you'll get nothing. Again, these settings are not useful for "tweaking" reception. "

Not correct; I can decode with P25 800 MHz or P25 Standard. If it does not make a difference why include it?
This is exactly the reason I don't join clubs. Perhaps the self-appointed N_Jay will set us straight.

QRT

 

[Dewey]

As far as I've read, there have been no reports of held talk groups being silent, or particular transmissions within a conversation being missed, and other troubles consistent with system tracking. From everything I've read, it's a straight reception problem leading to a decoding problem, such as a signal "fade" in the middle of the transmission. I, personally, have had no trouble "tracking" the system when it's in range, only some problems actually receiving the system in locations where it used to work. This is consistent with what I've read, too.

The table/band plan information is transmitted thru the CC. Hopefully tomorrow, I'll have time to decode it again and will post it here.

I'm hoping that you will discover something that we have been missing. This has become a very long thread, so we are probably dealing with several issues here. I went back and found some of the posts that led to my last comment about the possibility of something in the tables or band plan not being known, and here they are:

http://forums.radioreference.com/ma...altimore-system-discussion-4.html#post1477591
http://forums.radioreference.com/ma...altimore-system-discussion-5.html#post1479178
http://forums.radioreference.com/ma...ltimore-system-discussion-11.html#post1518015
^ This might be a firmware problem ^
http://forums.radioreference.com/ma...ltimore-system-discussion-11.html#post1518130
^ Troy's last paragraph is interesting in this post ^
http://forums.radioreference.com/ma...ltimore-system-discussion-13.html#post1519299
^ This is the post I was referring to about holding versus scanning ^
http://forums.radioreference.com/ma...ltimore-system-discussion-13.html#post1519346
^ This might be related to Troy's comment about having only one control channel programmed ^
http://forums.radioreference.com/ma...ltimore-system-discussion-14.html#post1519798
^ Another post about it sometimes working, sometime not ^
http://forums.radioreference.com/ma...94926-new-baltimore-system-discussion-14.html
http://forums.radioreference.com/ma...ltimore-system-discussion-16.html#post1523953
^ Another post about working when scanning, but sometime not working when holding ^

No argument, just one person's input and as always...

I reserve the right to be wrong

Dewey

 

[Idontknowradio]

No issues

My XTS 5000 works perfectly on the City System!!!!

 

[pratzert]

my xts 5000 works perfectly on the city system!!!!

xts5000 msrp $4,400.00

gulp !

 

[damorg5623]

What do you recommend for those of us who purchased a Radio Shack PRO96 Scanner, and just like to listen and keep up with what is happening in our Baltimore City Police District?
Who might lack the knowledge to do these upgrades.
Is there any step by step procedures for us dummies?

 

[sfb88]

This is my first post here. I just 'upgraded' my PRO2096 to be able to listen to the newly changed system. I joined this site so that I would have database download privileges. I already had purchased tthe USB cable to upgrade firmware so I didn't need to get that. I purchased and downloaded Win96 software.

Note that the download from RadioReference will load the Baltimore system into one bank of a new blank template so if you just load this into the radio you will lose the other banks. This is easily handled by uploading your existing programming from your scanner and saving it. Then download the new programming from here. Use the copy to bank feature to overwrite the old bank of your saved programming. Then save this programming and upload it to your scanner.

I am away from my laptop and working from memory so I can't give specific names for menu selections but it wan not too difficult once I figured out a few things about the software.

 

[ka3jjz]

If you're using Win96, this wiki article has a snapshot that should be helpful...(all links are blue)

Programming the New Baltimore P25 System - The RadioReference Wiki

We don't have one for ARC96 (yet) but I would expect it to be similar

best regards..Mike

 

[damorg5623]

Hey sbf88 & Mike,
Thank you BOTH very much for you answers, and your help.
Hopefully, I'll be able to somehow figure this all out.
I'm disabled and I purchased this Radio Shack PRO96 Scanner about 5 years ago, sorta to keep me company, but also to keep me updated as to what was going on out there in the world.
I've missed not being able to use it for about 6-7 weeks now.
Thanks again !

Regards,

Dan

 

[sfb88]

Ka3jjz, a call sign from out of the past. I'm not a ham but I spent many Sundays listening to the BRATS Listening Post net. I really appreciated the job you did there.

 

[ka3jjz]

It seems like forever since I did the Net...thanks for the kind words...Mike

 

[doctordave]

I'm curious how folks are making out with monitoring the Balt City system, using a 996XT. I'm not impressed with the radio's performance when mobile in Balt. Presumably multi-path issues....the radio will have a very solid copy - and typically within a few seconds will revert back to scanning, then lock in again with a broken copy of the same transmission. I haven't stumbled upon any tweaks that seem to improve things. Attenuation is not helpful. From my house in Northern Balt County, I'm actually having better success monitoring the system with my 396T and an 800 ducky.

Thought I'd ask if anyone with a 996XT has figured a way to optimize performance - specifically when operating mobile. I have yet to place my GRE in the vehicle & give it a whirl....might be worth doing some side-by-side testing.

 

[ka3jjz]

Since it's been some time now, we could use the instructions on how to set up this system for the object oriented scanners and Home Patrol in our wiki. Questions about this are likely to crop up sooner or later. The article is here..

Programming the New Baltimore P25 System - The RadioReference Wiki

TIA Mike

 

[radioman2001]

I am not familiar with the Baltimore system, but it sounds like phase shift from the simul-multi-cast transmitters. (We have the same problems here with the NYC DOITT UHF system) You might want to try using a psudo diversity antenna system. Take 2 identical antenna's and place them several wavelengths from one another. (like both fenders on the back of the car) Run both coax's into a "T" connector into the radio's antenna port. The idea is that at least one antenna will get the signal, and I can't guarantee that it will work, but it might help, or make it worse you will have to try it.
In the early days of 800mhz Johnson radios had true diversity receivers and it made quite a difference in the outlining areas of early trunked systems.