This article first appeared in the July 2000 issue of Monitoring Times.


One of the most difficult challenges facing a trunked radio scanner listener is getting accurate information about system frequencies and talkgroups. Since few public safety agencies openly publish their complete system layout, it becomes a matter of trial and error to get everything right.

The Internet has become an important tool in distributing the details of trunked radio systems, through both the world wide web and electronic mail. This month we'll open the mailbag and report on the updates and new information readers have sent in. Please feel free to send me frequency lists and talkgroups of the systems you monitor and I'll share it with Monitoring Times readers here in print and on my webpages.

Evansville, Indiana

Chris Dees writes:

The Evanvsville, Indiana information in the LTR Trunking article needs to be updated. AMR Ambulance was using the 800 MHz system, but has switched to Mobex Midwest. Here's the updated information, straight from AMR and Mobex. I'm using a PRO-92 with no problems on LTR.

Mobex Midwest Communications
Location: Evansville, Indiana
Type: LTR
Frequencies: 863.4625, 864.4625, and 865.4625
Used By American Medical Response Ambulance Service (AMR)

AMR Talkgroups:

102010 Dispatch A (Medics)
102011 Deaconess Hospital Patch
106010 Dispatch W (Wheelchair Vans)
106011 St. Mary's Hospital Patch
110010 Administrative/Tactical
110011 Welborn Hospital

Also, Logan County, Kentucky is utilizing a Kenwood LTR system for its Emergency Operations Center (EOC):

Logan County EOC
Location: Russellville, Kentucky

Frequencies: 453.1875, 453.3250, 453.3625, 453.6125, 453.8000, 453.8375, 453.9250


001050 Logan County Sheriff Dispatch
001051 Logan County Sheriff Channel 2 (called "SO2")
001052 Logan County Court Security
001054 Russellville Police Dispatch
001058 Logan County Mutual Aid Channel
001059 Logan County Fire Channel 1
001060 Logan County Fire Channel 2 (?)
001061 Logan County Rescue Squad
001062 Logan County Detention Center

Bob Schapker also wrote in about Evansville, providing somewhat different information:

There are actually two ambulance services using Mobilenet. The first is AMR, the largest private ambulance provider in the US, and the other is ASAP Ambulance, a small private ambulance provider.

AMR has recently changed to 856.4625, 857.4625, and 858.4625 and interestingly the main channel they use is 820.4625. ASAP Ambulance uses the LTR system but they have recently returned to using 155.295 MHz with 100 kHz tone as the primary ambulance channel due to poor coverage in the metro Evansville area. The coverage issue is also the reason for AMR's switch with a single tower on the far west side of Evansville, since coverage on the more populated east side was spotty. Scanner listeners looking for Evansville Ambulance should try 820.4625 MHz since AMR has the city and county contract for E-911 coverage.

Headquartered in Aurora, Colorado, American Medical Response (AMR) is the largest provider of emergency and non-emergency ambulance services in the U.S. AMR operates in 36 states and employs more than 20,000 people in 265 operating sites, transporting over 4 million persons per year in a fleet of more than 4,000 vehicles.

Albuquerque, New Mexico

Bill Tobin wrote in with a number of detailed messages covering three EDACS systems currently operating in Albuquerque, New Mexico:

City of Albuquerque (ABQ) EDACS system WNSS410 in correct Logical Channel Number order:
LCN Frequency
1 856.2625
2 857.2625
3 858.2625
4 859.2625
5 860.2625
6 856.4625
7 857.4625
8 858.4625
9 859.4625
10 860.4625
11 856.4875
12 856.7125
13 857.7125
14 858.7125
15 860.9875

The Control Channel is channel 1.

Decimal AFSUser
0272 02-020
0273 02-021 ABQ city garbage pickup
0274 02-022
0275 02-023 unknown yet what this is
0276 02-024 ABQ city garbage pickup
0277 02-025
0278 02-026 ABQ city litter removal
0279 02-027 ABQ city garbage pickup
0280 02-030 ABQ city garbage pickup
0281 02-031 ABQ city garbage pickup
0282 02-032 unknown yet what this is
0286 02-036 tire shop construction foreman
0287 02-037 guardrail repair
0288 02-040
0289 02-041 Sun Tran Dispatcher broadcasts to busses
0290 02-042 Convention Center security
0291 02-043 Sun Tran Bus company operations
0292 02-044 Sun Van handicap van service
0293 02-045
0294 02-046 Sun Tran bus maintenance
0295 02-047 Sun Van dispatcher broadcasts to handicap vans
0304 02-060
0305 02-061 ABQ water department
0306 02-062 ABQ water department
0307 02-063 ABQ water department well maintenance crews
0308 02-064 ABQ water department, customer service, sewer
0309 02-065 ABQ water department

Notes: Sun Tran bus to dispatcher conversations cannot be tracked in trunked mode. These conversations occur in conventional simplex mode on a channel that is not currently in use. The busses never talk to each other directly; all conversations go through the dispatcher.

The ABQ water department conversations are confined to LCN's 11 to 15, while all of the other talk groups are on LCN's 2 to 10.

1 866.250 866.225
2 866.5625 866.4750
3 866.7625 866.7375
4 866.975 866.95
5 867.25 867.2
6 867.600 867.475
7 867.975 867.7125
8 868.2625 867.95
9 868.5000 868.2375
10 868.75
11 866.1125
12 866.45
13 866.7125
14 867.0625
15 867.45

The same talk groups show up on both of the WPMU757 and WPMX854 systems, with the traffic load shared about equally between the two systems. If one system fails, the other system will pick up the entire traffic load.

This new ABQ 800 MHz system is replacing the old VHF police and fire channels. All of the VHF police channels, except the west substation frequency 154.815 MHz, are now dead and on the new system.

Some of the old VHF City of ABQ and Bernalillo county fire frequencies are now also dead. The main city of Albuquerque fire frequencies are still operating in parallel with the 800 MHz system.

In other words, transmissions heard on the VHF frequencies on one scanner are also simultaneously heard on the 800 MHz system on the other scanner. This 800 MHz system is new, with transition from the old system to the new system still ongoing.

The bad news is that the new 800 MHz system is mostly digital radio. So, when someone is talking into their radio, all that is heard on my scanner are data bursts. The talk group number shows up on the display during the data bursts. Every once in awhile, though, voice is heard on the 800 MHz system. It does have voice capability. Sometimes the mobile is in digital mode, and the dispatcher is on voice mode during the same conversation. Why the transmissions are mostly digital with an occasional voice is unknown.

A police officer who visited our apartment house to give a presentation on crime prevention was very pleased with the new communications system.

The following talk groups were found. The data is very general because details cannot be identified when the transmissions are mostly digital.

Decimal AFS User
0528 04-020
0529 04-021 police
0530 04-022 police
0531 04-023 police
0532 04-024 police
0533 04-025 police
0534 04-026 police
0552 04-050 data heard; unknown what this group is
0553 04-051 data heard; unknown what this group is
0554 04-052 data heard; unknown what this group is
0558 04-056 data heard; unknown what this group is
0784 06-020
0785 06-021 ABQ police NCIC data
0786 06-022 ABQ police
0788 06-024 ABQ police
0790 06-026 ABQ police
0792 06-030 police
0794 06-032 police
0795 06-033 CID tactical
1040 08-020
1041 08-021 ABQ fire department west and southeast
1056 08-040
1057 08-041 ABQ and Bernalillo county fire department
1060 08-044 ABQ fire department
1280 10-000
1281 10-001 ABQ fire department northeast
1296 10-020
1297 10-021 data heard; unknown what this group is
1312 10-040
1313 10-041 data heard; unknown what this group is
1314 10-042 data heard; unknown what this group is

On the other new Albuquerque EDACS systems, I found the talk group numbers of the city fire tactical channels. They are:

Channel Talkgroup AFS
TAC 1 1121 08-121
TAC 2 1122 08-122
TAC 3 1123 08-123
TAC 4 1124 08-124
TAC 5 1125 08-125

And it turns out that these are digital. So, when the fire trucks arrive at the fire and switch to a TAC channel, all I hear on my scanner are bursts of data static. This is really amazing - the firemen are within feet of each other, and yet communicate with bursts of data! It used to be interesting listening to the old VHF tactical frequency; during the fire, I could hear all of the details of how the fire was being attacked. Now all I can hear is bursts of data.

Rochester Update

David Stark, NF2G, wrote to inform me of his scanning pages on the web at His New York trunking pages in particular are extensive and very helpful. The site is regularly updated and lists frequencies and talkgroups that aren't published anywhere else.

He also mentions:

With reference to your description of LTR behavior, particularly transmission trunking, you should know that I have never observed transmission trunking on any of the Rochester systems on 800 or 400 MHz. That might be due to the relatively light traffic loading on these systems most of the time. Users nearly always appear on their "home" channel and tend to stay there for the duration of most conversations. As these systems get busier and more customers are added, that could change.

Disneyland Update

Claude Cartee sent in the addresses of several websites containing additional information about the radio systems used at Disneyland:

He also reminded me that there is a Usenet newsgroup, alt.disney, which occasionally has postings from scanner enthusiasts who visit the park. Using the Usenet archive service at Dejanews will yield some interesting postings from the past.

Austin, Texas

The city of Austin, Texas, took a step forward in May when it announced a decision replace their 18-year old radio network with a new radio system from Motorola. If negotiations are successful and the City Council approves, the new $70 million system could be in operation within two years.

Motorola would install about 10,000 new radios in buildings and vehicles belonging to various Austin and Travis County agencies, which are expected to use nearly 90 percent of the system's capacity. State agencies and organizations will also make use of the system, including the Department of Public Safety, Department of Transportation, the University of Texas, the Texas House of Representatives and the Texas Legislative Council.

Although Williamson County, located north of Austin, recently installed a similar system from Motorola, the Interstate 35 corridor is home to a number of Ericsson users including the cities of San Antonio and San Marcos, Bexar County, the Lower Colorado River Authority and Bell County.

That's all for this month. I've started to build a new website for strictly radio-related issues, including trunked system information. You can check it out at, or follow the link on my original page at I can be reached by e-mail at either or Until next month, happy monitoring!

Comments to Dan Veeneman

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