Scanner Tales: Rise and fall of T-Band in the Chicago area

[N9JIG]

(Part 1 of 3)

The story below focuses on the suburban Chicago area. Very similar programs took place in other metro areas like New York, Boston and Los Angeles.

When I first started to be interested on police communications in the late 1960’s and early 1970’s police and fire operations were mostly on VHF high band. My local police were on 155.130, and my old Regency scanner rarely moved off this channel due to the dozen or more towns in our area that used it as well as the Wisconsin, Indiana and Michigan users I could hear often. Eventually my hometown moved to the new “T-Band” channels and I needed to get a new scanner.

2024 is the 50th anniversary of the startup of many of the numbered T-Band Networks set up in the suburban Cook County area surrounding Chicago. The Network Numbers ranged from 1 to 24 officially, with 5 more unofficially numbered ones in the border areas or adjacent counties. Most were on UHF T-Band from 470 to 476 MHz. (See below for the breakdown). The program originated in the early 70’s and was mostly completed by the end of 1974. The Network Numbers survive even today as the common name of some of the channels used by agencies, even when they have moved to other systems, mostly StarCom21.

In the early 1970’s the police departments in the suburbs of Chicago were almost universally using VHF High Band (mostly from 154 thru 159 MHz.), and usually simplex. There were a few outliers here and there, but the vast majority were sharing about a dozen frequencies. Then, as it is now, Chicago’s suburbs tend to be fairly small, these days from a few thousand up to about 50 thousand for the most part. Back then they were much smaller except for the close-in/boxed in and matured towns like Park Ridge, Winnetka, Berwyn and Riverside. Around the edges were some towns that were just starting to become recognized as suburbs, towns like Aurora, Elgin, Joliet and Waukegan. These towns were more like independent cities of their own before suburban sprawl grew to envelop them.

Chicago itself had recently moved to 460 MHz. UHF from VHF channels, some of those VHF channels were re-farmed out to some of the suburbs. Ny dad was heavily involved in the CPD UHF transition, he worked for Illinois Bell Telephone and was the project manager for the then new communications system and helped redraw some of the District boundaries to match the telephone exchange boundaries to make it easier and cheaper to route calls to the proper desk based on the exchange the call originated from.

Cook County itself used VHF high band as well for the Sheriff’s Police. Originally on 159.090 they soon thereafter established new North (155.595) and South (155.535) repeaters and a couple other channels for their use. Neither Cook County Sheriff nor Chicago PD were considered for T-Band channels at the time.

During the 1950’s and 1960’s post-war Chicagoland suburbs grew exponentially, and this didn’t really stop in the 70’s. Some of the further out suburbs like Plainfield or Elgin are still growing quickly today. With no end of growth in sight, police departments communications needs grew as well. With upwards of 20 growing towns sharing a single channel, the channels were overwhelmed. Sooner or later this problem would come home to roost. That day was October 1, 1972. Police Officer Anthony Raymond of the Hillside police department made what he presumed would be a routine traffic stop on a car entering an expressway. What he couldn’t know was that the occupants of that car had just committed an armed robbery.

Somehow, they got the drop on Officer Raymond, kidnapped him, then strangled and stabbed him to death. His body was eventually buried in a field in northern Wisconsin, not to be found for almost a year. Over the next year after his body was found suspects were identified and arrested for his murder as well as another, of an 18-year-old girl found buried near the officer’s body.

One of the reasons he was not found to be missing as quickly as one would expect was that he could not get thru to dispatch on his radio. The simplex radio channel (155.490) that Hillside shared with more than a dozen other towns in the area was so busy that most traffic stops and other “routine” radio traffic we take for granted today just didn’t happen. When they were called in, they were often stepped on by other towns sharing the channel. Too many towns and not enough channels made a dangerous combination, and that cost Anthony Raymond his life. He was 25 and been on the job for 3 years. He had 2 small sons and a wife at home.

While discussions of what to do about the situation in this area, as well as other metropolitan areas around the country, had been happening for a while, this was the spark that lit a fire under the feet of politicians, engineers and police officials. The police communications issue had to be addressed, and it needed to happen NOW.

As of 1972 about a dozen VHF channels, like 155.190 (35 suburbs, with a combined population of about 465,000) or 155.490 (17 suburbs, with over 300,000 people) were used by the 120+ towns. Some of those channels were also heavily used by agencies in other counties in the area. Only a couple were already using repeaters, so in order to make the rest repeaters more scarce VHF channels would be needed. Add to that, distant stations were commonly heard from all over the Midwest, especially on summer evenings when “Skip” conditions were common.

Concurrently the federal government had a grant program called Law Enforcement Assistance (LEA). These grants were to be used to modernize police procedures and equipment. The studies funded by these grants proved the need for a massive increase in the available frequency spectrum for police communications. These grants also eventually paid for much of the new radio equipment needed.

Also, during this time, partly as a result of all these discussions, the FCC reallocated UHF TV channels 14 thru 20 (470 thru 512 MHz.) in the largest metro areas to land mobile use on a shared basis with the existing TV stations, with a portion reserved for public safety use. This is commonly referred to as “T-Band” or “Television Sharing Band”. The ten largest metro areas were allocated one or more 6 MHz. segments, corresponding to TV channels based on need and availability so as not to interfere with existing TV stations. The Chicago area was allocated TV Channels 14 (470-476 MHz.) and 15 (476-482 MHz.) but only Channel 14 was used at first due to some “Safe Harbor” issues with Channel 15 and TV stations using it in the Midwest. Channel 15 was eventually released but well after the first systems were established.

In 1972 the Illinois Institute of Technology (IIT) published an exhaustive study of police communications in Cook County, Illinois. While dominated by the City of Chicago, Cook County is also home to over 120 suburbs, almost all of which had their own police departments and most of them also had their own dispatchers, while a few were dispatched by neighboring towns.

Each 6 MHz. TV channel (Channel 14 in the Chicago area) was split into 2 segments. The lower 3 MHz. (470 to 473 on Channel 14) was reserved for repeater outputs or base operations and the higher 3 MHz. (473 to 476) was reserved for mobile use. This was a relatively orderly way to set up repeater pairs, compared to the VHF high band which had no specific relationship between the repeater output and input. 3 MHz. separation of repeater and mobile inputs was chosen as it is half of the available spectrum. Decades later when 90 MHz. of spectrum in the 800 MHz. band was set aside for land mobile and cellular use the inputs were set at 45 Mhz. apart for the same practical reason.

From there individual channels were set up at 25 KHz. apart but on the “odd” channels. Instead of frequencies like 470.100 and 470.125, the channels were offset by 12.5 KHz. so that the channels would be 470.1125 and 470.1375 and so on. Why this was done is anyone’s guess. A couple decades later the channels in-between would be authorized for use to effectively double the available channels.

(Continued in Part 2)

 

[N9JIG]

(Part 2 of 3)

40 of the T-Band channel pairs were to be reserved specifically for public safety use, this came out to 1 MHz. of the 3 MHz. worth of output channels plus the corresponding mobile channels. While the primary intent was for police operations, other services like fire and public works could be licensed if channels were available. Other T-Band channel pairs were set aside for other land mobile users, like business, transportation and paging.

So now that we have 40 new channel pairs for police agencies, how are they going to be allocated? During the study period IIT engineers contacted all the police departments on Cook County and asked how they thought things should work. Looking at these results as well as things like practical and political relationships between communities, geography and, of course, current and projected channel loading, a plan was set up. In Cook County about 20 of the channels were assigned by the study to numbered “Networks”. Due to the large size of the county some channels were allocated to two or more Networks on different sides of the county as they could be accommodated without interfering with each other.

In addition to the T-Band channels the various VHF channels were allocated to some communities. A few towns already had repeaters or wished to remain on VHF for whatever reason. Since many of the other users would move off to T-Band the activity levels would lessen on the VHF channels so this could be a viable option. A couple were already in use by the agencies assigned in the study. Some others appeared to be kind of random, but I am sure there was some sort of reason for them.

For the most part the proposed plan was accepted and implemented. There were some changes made after publication as a town decided it would prefer to be grouped with a different network that originally assigned. A couple towns proposed for moving to UHF declined and stayed on VHF and their slots were given to others. Some Networks were deemed to be too large and were split up to a second channel. Some of the UHF channels were changed as adjacent channel issues and conflicts with neighboring counties became known.

Communities were also encouraged to form consortiums for purchasing of infrastructure. This was done by making these a higher priority in grant allocations. Central Dispatch agencies were also encouraged. Communities had a much better chance of getting lucrative grants if they banded together to create either Central Dispatch agencies or share infrastructure. This also reduced the per-town costs as they could leverage the economies of scale.

While the IIT report focused solely on suburban Cook County, both Lake and DuPage Counties in Illinois and neighboring Lake County Indiana were also assigned channels out of the 40 channel pairs in T-Band. This meant that most of these channels had at least 2 networks on them within the 4 counties involved.

The plan envisioned 24 new networks for Cook County suburbs, 18 on the new 470 MHz. T-Band channels and the rest on existing or reassigned VHF pairs. There were a couple networks assigned 2 T-Band repeaters, and a couple channels reused within Cook County. The 6 VHF networks were assigned 2 frequencies each, one as a repeater input and another for the output. Of course all UHF T-Band channels were assigned in repeater/mobile pairs.

In addition, there were several “Area Channels” assigned for mutual aid and coordination, 2 on VHF and 3 on UHF. Then there were 6 “Reserve Pool” channels for expansion. The frequencies chosen were coordinated with plans for the other area counties’ plans.

After the assignments were made, grants applied for and approved, construction started. Motorola and GE received most of the contracts for portable and mobile radios as well as base station infrastructure like repeaters, remote receivers and consoles. This was the era of Micor and Mastr-II mobiles and MX300 and PE portables, so these were bought by the hundred lot with the free-flowing federal money.

The frequencies assigned to the various networks were changed here and there to prevent interference from other networks and towns dropped out of one network and joined others. Some towns assigned to networks changed their minds and remained on their old VHF channels and others assigned VHF joined UHF networks with their neighbors. One network was split in two, with an “A” and “B” number to prevent overcrowding.

Some of these alterations and changes were interesting in their own light. A couple tidbits I found fascinating (and I was involved in after the fact) include the below:

• Network 24 (470.7625) was originally assigned to 7 communities on the North Shore (Winnetka, Wilmette, Wheeling, Glencoe, Kenilworth, Northbrook and Northfield). This was deemed too crowded as Wheeling and Northbrook were expected to grow and the other 5 had historically been linked by coordination and demographics more so that with Wheeling and Northbrook. They applied for and received a second channel (470.6625) and called the original channel “24-A” and the second “24-B”. Both of these networks as well as a couple of others in the area (22 and 21) formed a consortium called “Norcom” (North Regional Telecommunications Network). They also had an areawide mutual aid channel, a tactical repeater, a Point-to-Point channel and a mobile tac channel, all on UHF T-Band. While originally Net 22 was assigned a VHF channel pair they received a UHF pair when they joined up with Norcom to provide continuity and interoperability. Each town had their own dispatch centers and the radio equipment was bought from GE. They maintained a strong cooperative effort that continues to this day, although due to consolidation requirements from the state most of the smaller towns are now dispatched by Glenview. During the last 50 years of Norcom several channels had changed around from the original plan.
• 
  
• NetCom was a consortium of several other networks that stretched from as far south as Berwyn and Cicero to as far north as Park Ridge and Des Plaines. They had 4 dispatch repeaters and coordinated the purchase of the radio equipment as well as radio numbers. Each town had their own dispatch centers, and after the equipment purchase and installation all pretty much did their own thing. Des Plaines opted out of T-Band and retained their own VHF repeater for decades, finally switching over to StarCom21 not too many years ago. The slot they had on the channel to be shared with Park Ridge and Rosemont was then granted to Triton College. Since they were pretty far away from the repeater located at Park Ridge they put up their own lower-power repeater on the same frequency (470.4875) with a different PL. In Rosemont and parts of Park Ridge one could hear the Triton repeater if the PL was switched off or the slight heterodyne when both were active.
• 
  
• Northwest Central Dispatch in the Arlington Hts. area as formed by 4 towns assigned to Network 19 with 2 channel pairs. Originally one was used for dispatch and the second used for a go-to/info channel but due to congestion in the growing towns it was split into two dispatch channels. The original four towns (Arlington Hts., Buffalo Grove, Mt. Prospect and Elk Grove Village) were later joined by others in the area after T-Band was replaced by 800 MHz. trunking. NWCD is now one of the largest central dispatch facilities in the state.

(Continued in Part 3)

 

[N9JIG]

(Part 3 of 3)

Most of the rest of the Cook County suburbs banded together to form consortiums in much the same way as Norcom and NetCom, get a joint grant to build the infrastructure and by the radios and then did their own dispatch.

Around the area, DuPage County also got busy on T-Band. Originally it was split up into 4 quadrants and each assigned channels and encouraged to form a dispatch center. DUCOMM became the largest and absorbed several of the communities from several quadrants. It is now one of the largest central dispatch agencies in the state and once had over a dozen UHF T-Band repeaters. While now most operations are on StarCom21 there remains some use of 470 MHz. T-Band there for rebroadcasts of the local mutual aid operations, radio techs and perhaps other purposes.

Other DuPage central dispatch agencies came and went over the years, many of the towns ended up with DUCOMM. Southeast DuPage Communications (SECOMM) was the best known but broke up years ago. Some towns had T-Band channels that were not part of the larger groups or remained on VHF. Many of these operations have also switched to StarCom21.

Up in Lake County IL they also had several UHF T-Band channels. Like many Cook County operations most were cooperatively purchased and constructed. Some towns stayed on VHF though, especially in the Round Lake and Highland Park area. Again, many of these operations have since switched to StarCom21.

Kane County had some T-Band channel assignments as well, these were part of the Tri-Com and QuadCom dispatch systems.

Lake County Indiana also had T-Band assignments but the penetration there was not so deep. Only a few channels were used by a some of the towns close by the Illinois border.

Will County had a couple towns on T-Band, but these bordered Cook County and were tied into the Cook County systems.

With the original T-Band allocations for public safety reserved for suburbs, none of the various county sheriff’s police departments nor Chicago PD were given allocations. Chicago had their 460 MHz. system, still relatively new at the time. Before that they were mostly on 150 MHz. channels, some of which were reallocated to suburban use. The several counties in the area, (Lake, Cook, DuPage, McHenry etc.) remained on VHF high band. Eventually they moved most operations to 800 MHz., Lake and Will Counties to EDACS systems, Cook to a Motorola trunking system and DuPage to a set of 800 MHz. conventional repeaters.

Eventually TV Channel 15 (476-482 MHz.) frequencies were released for use in the area. Some of these went to Chicago, some to the suburbs. In addition, T-Band channels outside the 40 Public Safety reservations were obtained by city and suburban agencies. Eventually Chicago moved many operations to T-Band, especially at the two main airports. Other later users of T-Band included the Metro Sanitary District and the CTA. Again, these were not part of the original allocations nor were they considered in the IIT study.

When most Land Mobile radio services were mandated to go to “Narrow Band” around 2007-2010 some networks still using T-Band followed thru. Some waited, as around the same time T-Band was slated to be sold off to commercial interests at auction. While the auction money was promised to existing agencies using T-Band it was assumed (Correctly as it turned out) that money would never be seen. It was also predicted that the whole T-Band takeaway would fail anyway, it did. By that time however the damage had been done. Most T-Band users in the suburbs ended up on StarCom21. While most of these probably would have eventually anyway, the whole T-Band takeaway debacle expedited the process by many years.

Original Assignment Table

This table shows the original assignment of the new 1970’s Network Numbers as assigned by the 1972 IIT Report. The “Final Freq” field shows the eventual frequency used by most of the communities from the original assignments. Some towns swapped networks, either before operations commenced or afterwords. The last column indicates a shared infrastructure consortium if a formal name was established. There could have been others the author is unaware of. Later, around 2016 or so, a state law was passed to mandate consolidation of small 9-1-1 centers, this resulted on many of these networks being reworked and eventually replaced by StarCom21 or the Cook County system.

Nr	Original Assigned Freq	Final Assigned Freq	Area	Notes
1	470.4375	Same	Chicago Hts., Sauk Village Area
2	470.7625	Same	Matteson, Park Forest Area
3	154.860/155.670	470.9375	Homewood, Glenwood area
4	470.7375	155.190, 154.785	Orland, Tinley Park area
5	470.9375	Same	Calumet City, Lansing area
6	470.4625	Same	Oak Lawn, Alsip area
7	470.9875	470.8625	Palos area
8	155.580/155.190	470.7375	Crestwood, Calumet Park area
9	470.8125	Same	Harvey, Dolton area
10	470.9625	470.5875	Bedford Park, Justice area
11	470.8625	155.070	LaGrange area
12	155.310/154.950	471.2625	Berwyn, Cicero	NetCom
13	470.6625	155.070	Riverside area
14	154.845/156.090	Same	Oak Park Area
15	470.6375	471.2875	Norridge, Schiller Park area	NetCom
16	155.490/155.640	471.2375	Melrose Park, Franklin Park area	NetCom
17	470.8375	470.4125	Hillside, Maywood area
18	470.4875	Same	Park Ridge, Rosemont	NetCom
19	470.4375, 470.3125	Same	Arlington Hts, Elk Grove area	NWCD
20	470.3375, 470.3625	Various VHF	Schaumburg, Palatine Area
21	470.6125	470.7875	Skokie, Lincolnwood	Norcom
22	155.700/155.520	470.7125	Glenview, Niles, Morton Grove	Norcom
23	470.5625	Same	Evanston
24A	470.7625	Same (“A”)	Wheeling, Northbrook	Norcom
24B	470.6625 (“B”)	Winnetka, Wilmette area	Norcom

Conclusion:

The combination of the IIT report, grant money from the LEA and the critical need for police radio communications improvement in the 1970’s undoubtably save lives, of civilians and police officers. New technologies, like mobile data, video and the need for even more voice communications drove the resultant T-Band operations to be replaced by turning (mostly StarCom21 these days). Those of us who lived thru the transition to T-Band 5 decades ago and remember the chaos before T-Band can attest at how well the system worked compared to the old patchwork of legacy VHF channels.

Many agencies kept the old VHF channels for backup or Car-to-Car use. A different program that came about in the same era called “ISPERN” (Illinois State Police Emergency Radio Network) provided VHF mobile radios with the new ISPERN radio frequency (originally 154.680, later changed to 155.475) to any police agency that wanted them. The rules were that ISPERN had to be in Channel 1 and that the priority scan could not be disabled. Agencies were free to add their own channels to the other channel slots, many took advantage and added their old VHF channels to the F2 slot while others used their Public Works channels in the same way. To this day many of the channels that had been in used as early as the 1950’s are still used in one capacity or another by some agencies while T-Band has all but been abandoned.

 

[nd5y]

At that time where there any TV stations on ch 14 or 15 that were forced to move?

 

[N9JIG]

Not in the Chicago area but there were in other parts of the country.

 

[RFI-EMI-GUY]

Did Metropolitan Enforcement Group ever move from VHF 154? to T band? I remember picking them up locally on an old Regency Monitoradio (tube type) .

 

[N9JIG]

Did Metropolitan Enforcement Group ever move from VHF 154? to T band? I remember picking them up locally on an old Regency Monitoradio (tube type) .

Not on a dedicated frequency. They moved around a lot in the latter years before the Cook County unit was disbanded, depending on what they needed at the time. They may have also used some of the commercial services here and there.