Baltimore City

FIRST, please read the Simulcast digital distortion article to understand what is going on and why you may be having trouble receiving the system.

This topic is being discussed here. The database entry for the new system can be viewed here

Please use this article to document tricks, settings, and anything else that can be used to program the current crop of digital trunktrackers to correctly track the new Baltimore City P25 system.

Programming System Frequencies

Using the Pro96 CC Dump monitoring utility, it appears that there is a constant data stream (not the control channel) that hops between system voice frequencies. It may be the fire station signalling data, which constantly interrogates the fire station signalling units to verify connectivity. This stream hops between system frequencies, but never uses any of the four eligible control channel frequencies. Your scanner may momentarily confuse this data signal as the control channel, which could delay your scanner while it searches for and acquires the control channel. For this reason, it is recommended that you only program the four control channel eligible system frequencies into your scanner.

Pro-96/Pro-2096

Win96

Thanks fmon

PSR-800/Pro-18

Programming of the Baltimore City system on the PSR-800 requires simply that you obtain the most up-to-date library download via the EZ Scan software that came with the radio. Using that software, allow the library to be updated on the PSR-800. After that update is complete, you can simply import the system from the library using either the software or directly from within the PSR-800 Browse Library function.

Note: In order the find new talkgroups not submitted/published the Radio Reference, you must use the EZ Scan software to create a "Wildcard" object. Once this step is completed, you then must copy the system to the scanner.

Within the city limits, the radio and this "default" programming appears to do fairly well. However, reports are still coming in on issues with reception.

One tweak that helps (but has side-effects that you must consider*) is to only program in the single active control channel frequency to avoid having the radio drift and try to search other frequencies. This can only be done using the EZ Scan software. Of course the side-effect* is that if the control channel frequency changes, you'll hear nothing until you (a) notice this has occurred and (b) reprogram the radio with the new control channel frequency.

Also see the GRE/RS_PC_Object_Oriented_FAQ for additional settings in the error correction and noise threshold areas that might help, as this is a LSM system

Uniden DMA Scanners

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  1.Non-XT System screen

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  2.Non-XT Site screen

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  3.XT System screen

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  4.XT Site screen

• Note that the way the pre-XT scanners and XT scanners define P25 systems is different
  • For the 396T and 996T be sure to set your system type to Mot Type II / P25 and site type (applicable to the 996T) to Mot P25/P25 Standard
  • Also see the P25 audio decode level adjustment article, as well as the the following sections in the Easier to Read manuals;
    • Optimizing P25 Performance - Easier to Read 396T Manual
    • Optimizing P25 Performance - Easier to Read 996T Manual
• For the 396XT and 996XT both the system and site types should be P25 Standard.
  • See these sections in the Easier to Read manual for Optimizing P25 decoding
    • Optimizing P25 Performance - Easier to Read 396XT Manual
    • Optimizing P25 Performance - Easier to Read 996XT Manual
• Examples using FreeScan are shown above (Images 1-4). Additional examples are solicited.

Other Digital Trunktrackers

• It's been noted in the above thread that the current list of Uniden and GRE/RS digital trunktrackers (with the exception of the PSR-800) do a very poor job of decoding this system. It's likely this has to do with both the multipath issues and the LSM modulation, which evidently the current firmware cannot handle well. The information in the Uniden section should be used as an experiment and probably won't work well in most situations for this system.

Baltimore City System Radio IDs

RIDs identified using PSR-800. Duplicates marked with (D). I realize police units identify with different letters based on shift and radios may cross over, but these are listed as-heard to avoid future-reference confusion.

• 2260155 SQD 54
• 2260175 MED 12
• 2260221 ENG 14
• 2260508 BATT 4
• 2260750 TRK 16
• 2260877 ENG 2
• 2260910 ENG 57 PTBL
• 2260994 MED 14
• 2263611 8C35
• 2263722 8A11 (D)
• 2263801 4C36
• 2263887 8A10
• 2263888 8A21
• 2264142 8A22
• 2264145 8A32
• 2264223 8A34
• 2264227 8A35
• 2264361 KGA SW DISP
• 2265266 8C15
• 2265446 SW 4
• 2265508 8A09
• 2265858 8A14
• 2265928 8A11 (D)
• 2265931 8C26
• 2265937 8C12
• 2265940 8C91
• 2265976 8A12
• 2266010 8A36
• 2266013 8801
• 2266039 8A39
• 2266042 8A33
• 2266408 8A15
• 2266416 8C14
• 2266543 8850
• 2266544 8C11
• 2267313 7803 K9
• 2267352 8A26
• 2267755 8C14
• 2268036 FOXTROT UNK
• 2270179 A3 EMS1 OPER
• 2275353 KGA SW DISP
• 2276536 KGA CW OPER
• 2279324 A6 FG2 OPER
• 2279399 EMS OPER
• 2279543 A3 EMS1 OPER
• 2279835 A2 MAIN DISP
• 2279979 A2 MAIN DISP