When you boil it down, besides the proper scanner, success in monitoring trunked radio systems requires information about radio frequencies and talk groups. Frequency listings can be found in many places, including the official database of the Federal Communications Commission (FCC). However, finding talkgroup information is more of a challenge, and even when you do find a list, what if it doesn't match up with what you're seeing?

Los Angeles, California

Dan,

I recently bought a Radio Shack PRO-95 1,000-channel scanner, and it's working quite well. However, I have a question related to trunking. I'll try to be as succinct as possible. Here goes: I programmed 20 trunked Los Angeles city frequencies (EDACS) into one of the banks. The PRO-95 is so far scanning and tracking them flawlessly, but I'm confused by the talk group ID numbers. The numbers that the scanner displays, such as 0179 or 2450, don't appear to match any of the talk group ID numbers listed in my 2003 edition of POLICE CALL.

What gives? Do they change the ID numbers all the time? Are there far more ID numbers in a given system than are listed in POLICE CALL? Am I missing a step? Please let me know.

I truly appreciate your taking the time to respond. Thank you.

Chris in Redondo Beach, California

The city and the county of Los Angeles both operate EDACS (Enhanced Digital Access Communication System) trunked radio networks. Talkgroups in EDACS systems are made up of three parts, Agency, Fleet and Sub-fleet, which are abbreviated as AFS. An Agency may have many Fleets, while each Fleet may have numerous Sub-fleets. AFS is usually shown in the format AA-FFS where AA is the Agency, FF is the Fleet and S is the Sub-fleet. Much more information about EDACS can be found in my April 2000 Tracking the Trunks column.

Newer trunk-tracking scanners that support EDACS default to displaying talkgroups in AFS format rather than a simple decimal number. However, based on your letter, it appears your PRO-95 may be showing talkgroups in decimal rather than AFS format.

ID numbers typically don't change that often, but you need to keep in mind the source of talkgroup information. In general, almost all of the lists you read come from scanner listeners like yourself, since very few public safety agencies are forward-thinking enough to release their talkgroup organizational charts. What this means is that published information is almost always incomplete and reflects only what listeners have been able to work out. You may be hearing traffic in talkgroups that others have not managed to catch or figure out and publish. Also, in the case of such a large network as Los Angeles, system operators may occasionally move talkgroups from one system to another, causing existing talkgroup lists to immediately become out-of-date.

In any case, after listening to the traffic on a particular talkgroup for a while you should be able to figure out which city or county department is using it, and will soon develop your own talkgroup listing. Of course, please send in whatever results you obtain!

For those wishing to scan EDACS traffic, recall that the frequencies must be entered in Logical Channel Number (LCN) order or trunk tracking will not operate correctly. In the following frequency listings there are some gaps - leave the slot empty as you're programming your scanner so that all of the frequencies are kept in the proper sequence.

The L.A. County network actually has three distinct systems.

System A frequencies, in LCN order:

01 866.0625

02 866.4375

03 blank

04 blank

05 blank

06 867.9375

07 blank

08 blank

09 blank

10 blank

11 867.4375

12 867.7500

13 blank

14 blank

15 868.4375

16 868.5875

17 blank

18 blank

19 blank

20 868.3000

System B operates on the following frequencies, in LCN order: 866.0875, 866.5875, 866.9375, 867.2250, 867.7250, 866.2500, 866.7750, 867.7750, 868.0875, 868.7750, 868.7250, 866.3000, 866.2750, 866.8000, 867.2750, 867.8000, 868.2750, 868.8000, 867.2500 and 868.2500 MHz.

System C uses 866.2250, 866.7250, 867.3000, 868.2250 and 868.7500 MHz.

The following is a list of some of the County talkgroups. The first column contains the talk group in decimal form. The second column is the same talk group but in AFS format.

1057 08-041 Animal Control 1

1058 08-042 Animal Control 2

1169 09-021 Coroner 1

1170 09-022 Coroner 2

1171 09-023 Coroner 3

1185 09-041 District Attorney Dispatch

1186 09-042 District Attorney Tactical 1

1187 09-043 District Attorney Tactical 2

1125 08-125 Public Works Emergency Management

1126 08-126 Fire Emergency Management

1129 08-131 Sheriff Emergency Management

1130 08-132 Los Angeles City Emergency Management

1132 08-134 Emergency Operations Center

1133 08-135 Emergency Operations Center (All)

1233 09-101 Flood Control Dispatch

1234 09-102 Flood Control (East)

1235 09-103 Flood Control (West)

1236 09-104 Flood Control (South)

1356 10-094 Safety Police (Common)

1425 11-021 Parks Dispatch (North)

1426 11-022 Parks Dispatch (East)

1427 11-023 Parks Dispatch (South)

1428 11-024 Parks Tactical 1

1429 11-025 Parks Tactical 2

1217 09-081 Public Works Administration

1218 09-082 Public Works Survey

1219 09-083 Public Works Construction

1249 09-121 Road Maintenance Dispatch

1250 09-122 Road Maintenance 1

1251 09-123 Road Maintenance 2

1252 09-124 Road Maintenance 3

1253 09-125 Road Maintenance 4

1254 09-126 Road Maintenance 5

1265 09-141 Water Works Dispatcher

1266 09-142 Water Works (South)

1267 09-143 Water Works (North)

1268 09-144 Sewer Maintenance (South)

1269 09-145 Sewer Maintenance (Control)

1270 09-146 Sewer Maintenance (East)

1271 09-147 Sewer Maintenance (South)

1272 09-150 Water Works/Sewer Maintenance Emergency

The Los Angeles City network has two linked EDACS systems. The frequencies I have are listed as follows:

System 2

01 866.1125

02 866.1375

03 866.3875

04 866.4125

05 blank (maybe 866.6125?)

06 866.6375

07 866.8875

08 866.9125

09 867.1125

10 867.1375

11 867.3875

12 867.4125

13 867.6125

14 867.6375

15 867.8875

16 867.9125

17 868.1125

18 868.1375

19 868.3875

20 868.4125

01 866.1875

02 blank (maybe 866.3375?)

03 866.3625

04 866.6875

05 866.8375

06 866.8625

07 867.1875

08 blank (maybe 867.3375?)

09 867.3625

10 867.6875

11 867.8625

12 868.1875

13 868.3375

14 blank (maybe 868.3625?)

15 blank (maybe 868.6875?)

16 866.1625

17 866.6625

18 867.1625

19 867.6625

20 868.1625

L.A. City talkgroups include the following:

33 00-041 Animal Control 1

34 00-042 Animal Control 2

35 00-043 Animal Control 3

36 00-044 Animal Control 4

65 00-081 Building and Safety 1

66 00-082 Building and Safety 2

67 00-083 Building and Safety 3

68 00-084 Building and Safety 4

69 00-085 Building and Safety Emergency Mgmt

161 01-041 Department of Transportation Administration

164 01-044 Department of Transportation (Central)

167 01-047 Department of Transportation (Southern)

168 01-050 Department of Transportation (Western)

169 01-051 Department of Transportation (Valley)

170 01-052 Department of Transportation Engineering

172 01-054 Department of Transportation Investigation

257 02-001 Harbor Director

258 02-002 Harbor Security

266 02-012 Harbor Dispatch

267 02-013 Harbor Tactical 1

268 02-014 Harbor Tactical 2

289 02-041 Housing Authority

449 03-081 Public Works (Central 1)

450 03-082 Public Works (Central 2)

451 03-083 Public Works (Central 3)

452 03-084 Public Works (Valley 1)

453 03-085 Public Works (Valley 2)

577 04-081 Parks and Recreation Base

578 04-082 Parks and Recreation Administration

579 04-083 Parks and Recreation Ranger

580 04-084 Parks and Recreation Rangers 1

581 04-085 Parks and Recreation Rangers 2

586 04-092 Parks and Recreation Zoo

Flagstaff, Arizona

Hi Dan,

Just wanted to say I enjoy your column. I live in Flagstaff, Arizona. Radio listening is my hobby, mainly shortwave and police scanning. I am disabled so the hobby keeps me busy. Flagstaff switched to an 800 MHz trunk system and in talking to my local police I found out they have an 11-channel system which they share with NAU University. Most frequency directories list the NAU system but don't list Flagstaff and they only list five of the eleven frequencies. Keep up the good work, I look forward to your column each month.

Yours Truly,
Rich

Northern Arizona University (NAU) operates a Motorola Type II system that is shared by the city of Flagstaff in Coconino County. The Federal Communications Commission (FCC) frequency database lists six frequencies: 855.2125, 856.2125, 857.2125, 857.9875, 858.9875 and 859.4375 MHz. I'm not sure what the other five frequencies would be, since they're not listed in the official FCC database along with the known Flagstaff and NAU license assignments. I do have the following talkgroups on the system:

9712 25F Flagstaff Police Records

9936 26D Flagstaff Police Dispatch

1616 065 NAU Police Dispatch

1648 067 NAU Police - B - Alternate

1680 069 NAU Police - C - Alternate

1712 06B NAU Police - D - Alternate

3216 0C9 Parking

6448 193 Maintenance

6544 199 NAU General Services

If anyone is aware of the any additional frequencies or talkgroups, please let me know via electronic mail!

Johnson County, Indiana

Johnson County, Indiana, just to the south of Indianapolis, began operating an 800 MHz digital system in January 2002 as a demonstration effort for Indiana's emerging statewide radio network called Project Hoosier SAFE-T (Safety Acting For Everyone - Together). Planning for SAFE-T began in 1997 with the goal of allowing separate federal, state and local agencies to communicate with each other. This shared system would replace older, overloaded systems as well as provide better coverage throughout the state.

SAFE-T is a Motorola ASTRO mixed analog and digital network. Using repeater sites in Franklin, Greenwood and Mooresville, the Johnson County system is now providing better and more reliable coverage for a dozen police departments and six fire departments on the following frequencies: 855.7125, 866.4750, 867.0375, 867.3750, 867.4750, 867.9000, 868.3750, 868.4500, 868.9000 and 868.9750 MHz.

Crawfordsville, in Montgomery County, joined the SAFE-T network last year. Frequencies in use in Montgomery County are 866.4875, 866.8875, 867.4125, 867.9375, 868.4625, 868.7625 and 868.9875 MHz.

Some of the known talkgroups on the SAFE-T network:

48 003 Johnson County Emergency Management

64 004 Johnson County Animal Control

80 005 Johnson County Jail

128 008 Johnson County Investigations

160 00A Johnson County Administration

176 00B Johnson County Emergency Medical Service

192 00C Johnson County Fire

208 00D Johnson County Fireground 1

224 00E Johnson County Fireground 2

240 00F Johnson County Fireground 3

256 010 Johnson County Fireground 4

272 011 Johnson County Fireground 5

288 012 Johnson County Fireground 6

304 013 Amity Fire Admin

320 014 Nineveh Fire Admin

336 015 Trafalgar Fire Admin

352 016 Whiteland Fire Admin

368 017 Needham Fire Admin

384 018 Clark Fire Admin

400 019 White River Township Fire Admin

432 01B Johnson County Fire Dispatch

448 01C Greenwood Fireground

528 021 Greenwood Fire Dispatch

560 023 New Whiteland Fire

608 026 Franklin City Emergency Medical Service

688 02B Franklin City Fire Dispatch

752 02F Edinburgh City Fire Dispatch

816 033 Bargersville Fire Dispatch

7456 1D2 Crawfordsville Police

7664 1DF Franklin City Police Car to Car 1

7680 1E0 Franklin City Police Dispatch

7728 1E3 New Whiteland Police Dispatch

7792 1E7 Greenwood Police (East)

7808 1E8 Greenwood Police (West)

7824 1E9 Greenwood Police Dispatch (East)

7840 1EA Greenwood Police Dispatch (West)

8000 1F4 Johnson County Sheriff Dispatch

28512 6F6 Indiana State Police District 42 Dispatch

That's all I have space for this month. Please e-mail me with any questions, comments or updates at danveeneman@monitoringtimes.com. You can always find more information, frequencies and links on my web site at www.signalharbor.com. Until next month, happy monitoring!