Chatham Emergency Management Agency Digital Talkgroups Revisited

This afternoon I'm revisiting a blog post from last month about CEMA talkgroups. Last month's post was about CEMA talkgroups being referred to as number/letter combinations such as 1A.

Today's monitoring has shed some more light on the designators for CEMA's talkgroups. As mentioned in the previous post, CEMA activity has been noted on TG 12496. It was in use today as CEMA and the Port Wentworth FD tested warning sirens. During that activity, the TG was referred to as "channel 1D." This would indicate that CEMA now has two groups of talkgroups for their use: a set of analog channels using A or ALPHA designators and a set of digital talkgroup using D or DELTA designators.

If TG 12496 is, as referred to, CEMA 1D and the D/DELTA talkgroups parallel the known analog talkgroups, we can extrapolate the following:

12496 - CEMA 1D

12512 - CEMA 2D

12528 - CEMA 3D

12544 - CEMA 4D

12560 - CEMA 5D

Future monitoring should indicate if those are the actual talkgroup assignments. I do have one note from December 2007 with radio testing on TG 12560. If anyone hears any activity on these talkgroups, please send me an email at kf4lmt @ comcast.net or post to the Scan Savannah Google Group.

Mac McCormick III, KF4LMT

CEMA Talkgroups

During a recent exericse that I monitored, both Port Wentworth and CEMA (Chatham County Emergency Managment Agency) referred to TG 6256 as CEMA 3 ALPHA. This was formerly referred to as just CEMA 3, so I've begun wondering if there is parallel set of CEMA channels using digital voice (with the analog channels in the portable radio's A bank and the digital channels perhaps in the B bank). I have heard CEMA activity on a digital talkgroup within the past year (TG 12496) but I have not been able to tie it to a channel designator, so there is one piece of evidence that could point in that direction.

Drop me an email or post to the Scan Savannah google group (there is a link at the bottom of this blog) if you've monitored anything similar or have additional info.

Mac McCormick III
KF4LMT

Monitoring Digital Talkgroups on the Chatham-Effingham System

SCMPD's switch to digital talkgroups has generated many questions about the system and scanners that can be used to monitor the new talkgroups.

• Have the system frequencies changed?
• Have the talkgroup IDs changed?
• Will my scanner monitor the digital talkgroups?
• What kind of scanner do I need to monitor the digital talkgroups?

The system frequencies have not changed at this point. At some time within the next year (probably), the system frequencies will change because of the Nextel funded rebanding process. When the system is rebanded the frequencies will change, the result of which will be the inability of older trunk tracking scanners to monitor the entire system (more on this later).

The talkgroup IDs have changed. Instead of the old 32### and 33### talkgroups that SCMPD was using, they are now using 53### talkgroups. According to RadioReference the new SCMPD talkgroups are:

53264 - A1 PCT 1 Car-to-Car
53280 - B1 PCT 1 Primary
53296 - C1 PCT 1 Records
53312 - A2 PCT 2 Car-to-Car
53328 - B2 PCT 2 Primary
53344 - C2 PCT 2 Records
53360 - A3 PCT 3 Car-to-Car
53376 - B3 PCT 3 Primary
53392 - C3 PCT 3 Records
53408 - A4 PCT 4 Car-to-Car
53424 - B4 PCT 4 Primary
53440 - C4 PCT 4 Records
53456 - A5 PCT 5/6 Car-to-Car
53472 - B5 PCT 5/6 Primary and Thunderbolt Police
53488 - C5 PCT 5/6 Records and Thunderbolt Police
53664 - Westside Municipalities Dispatch

Unless you have a P25 Digital capable scanner, you won't be able to monitor these talkgroups. The older analog only scanners such as the Uniden BC235XLT, BC245XLT, BC780XLT, and BC895XLT and the Radio Shack PRO 2050, 2051, 2052, 2053, 2055, 2066, 2067, 90, 91, 92, 93, 94, 95, and 97 will not be able to monitor the systems. Current scanners that can monitor the digital talkgroups are:

Uniden BC250D
Uniden BC785D
Uniden BC296D
Uniden BC796D
Uniden BCD396T
Uniden BCD996T
Radio Shack PRO-96
Radio Shack PRO-2096
Radio Shack PSR-500 (available Oct. 2007?)
Radio Shack PSR-500 (available Oct. 2007?)

Do you remember the rebanding process I mentioned earlier? When considering which digital scanner to purchase, you definitely need to take rebanding into account. Radios such as the Uniden BC250D and BC785D will not support rebanding. While they can probably be found used for much cheaper than the other scanners on the list, they will not monitor the system once it is rebanded. The rest of the scanners in that list will support rebanding according to their manufacturers. I would also bypass the BCD296 and the BCD796 because their memories are not as flexible as the last six on the list. The newer memory organization methods used by the newer Radio Shack and Uniden scanners make more efficient use of the available memory, allowing you to program more into the radio.

I've also been asked about programming software. Personally, I prefer Butel's ARC software. I use versions of their software to program a BC250D, BC796D, and a BCD396T. I have always been pleased with software and suggest it when asked. The 396 and 996 versions of the ARC software can interface with RadioReference (provided you have a membership) and can program systems into your scanner from RadioReference's system profile data. This is a very nice function that I've used for travelling to areas where I'm not very familiar with the radio systems.

Mac McCormick, KF4LMT
kf4lmt@comcast.net