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This article first appeared in the July 2000 issue of Monitoring Times.
READERS TRACK THE TRUNKS
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
Talkgroups:
| 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 | AFS | User |
| 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.
| LCN | WPMX854 | WPMU757 |
| 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
www.nf2g.com/scannist/index.html.
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 http://www.signalharbor.com,
or follow the link on my original page at
http://www.decodesystems.com.
I can be reached by e-mail at either
dan@decodesystems.com or
dan@signalharbor.com.
Until next month, happy monitoring!
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