Scanning History

[radioboy75]

Calling seasoned scanning or law enforcement veterans! I am interested in the history of scanners and police radio in Iowa. I know that the State Patrol (Hwy Patrol) used to use frequencies in the 42 MHz range back in the 70s and earlier, and the sheriff offices used to use frequencies in the 37 MHz range. But I've never seen a map or a plan with what frequencies were in use where. Like did the whole state use one frequency for State Patrol? I've heard there was a common sherrif net frequency that the dispatch centers could talk to each other on, but was that everyone's MAIN frequency? That would sure get busy on Saturday nights! I've also heard that the troopers and deputies used to monitor each others frequencies on scanners and talk on their own frequencies -- but since they could hear each other on their scanners, they could talk . . .

Anyway, if there's anyone older than me on here that might know the answers and the frequencies, I'd love to know. Also, if you have a map or a plan from way back when, I'd love to add that to my archives!

 

[Cashanova48]

I have a directory book from the 80's or 90's if any freq's from that time period would be helpful for you on your research.

 

[bw415]

My father worked for the sheriff department in Louisa County Iowa in the 1960s and 1970s. The HP used 42.580 MHz and Fairfield was their headquarters for southeast Iowa. Louisa County used 37.100 MHz. They also used what was called "point to point" on 155.370 MHz.

 

[radioboy75]

My father worked for the sheriff department in Louisa County Iowa in the 1960s and 1970s. The HP used 42.580 MHz and Fairfield was their headquarters for southeast Iowa. Louisa County used 37.100 MHz. They also used what was called "point to point" on 155.370 MHz.

I don't know about other areas of the state, but Point-To-Point is still in use up here in the northwest corner. It's about 50/50 with the regional call channel on ISICS. Some use point-to-point and some use ISICS. Normally if they don't get through on one, they'll try the other. Our Sheriff's office used to use 37.1 as well...

 

[bw415]

I don't know about other areas of the state, but Point-To-Point is still in use up here in the northwest corner. It's about 50/50 with the regional call channel on ISICS. Some use point-to-point and some use ISICS. Normally if they don't get through on one, they'll try the other. Our Sheriff's office used to use 37.1 as well...

Just a little history to show how crude things were back in those years:

The sheriff’s office was in the court house and during the day the radios were operated from there. After hours and on weekends, the radios were operated from the Louisa County Jail by my father and mother. The first floor of the jail was provided as the living quarters for the Sherriff and his family. The jail cells were above us on the second floor and the radios were in our dining room. My parents had external speakers in their bedroom and if a call came in, one of them had to get up and run to the dining room to answer the call.

 

[radioboy75]

Just a little history to show how crude things were back in those years:

The sheriff’s office was in the court house and during the day the radios were operated from there. After hours and on weekends, the radios were operated from the Louisa County Jail by my father and mother. The first floor of the jail was provided as the living quarters for the Sherriff and his family. The jail cells were above us on the second floor and the radios were in our dining room. My parents had external speakers in their bedroom and if a call came in, one of them had to get up and run to the dining room to answer the call.

That's wild. Yeah, I don't know for sure how it was up here, but I think it was fairly similar. I do know that the sheriff used to live in the jail with the cells upstairs. When I was a kid, that same building was still in use, but the residence had been converted into offices. One of the rooms had been changed into the dispatch room. That was next to the kitchen. I remember the buttons to start the civil defense sirens were just around the corner from dispatch, in the kitchen.

 

[mws72]

Back in 1976 when I came home from the Marines. Davenport PD was on 460.125 & .150 having moved from 155.010 in about 1970. Bettendorf had just moved to 460.375 from 155.250. Scott Co Sheriff was on 37.10 & 37.16. They used 37.10 when they needed to talk to units north of Parkview along the Wapsi. Most of Eastern Iowa Counties were using 37.100 including Clinton PD that used voice inversion scrambling. By then the state was moving the Patrol to high band VHF. The state techs designed a frequency layout for the state in the 37.10s so the counties used 37.100 as common and another frequency for dispatch. Sometimes Davenport and Scott Co would patch their dispatches together for major incidents.
Cedar Rapids PD had just switched to UHF from several 39.xxx channels.
When the state set the VHF high plan there were changes due to frequencies being used in bordering states. Clinton Co was assigned 154.845 and 155.535. But 154.845 was already used by the Illinois State Police district in Rock Island and 155.535 was used by Jo Daviess County IL. so they were replaced by 154.965 and 155.520.

 

[radioboy75]

Back in 1976 when I came home from the Marines. Davenport PD was on 460.125 & .150 having moved from 155.010 in about 1970. Bettendorf had just moved to 460.375 from 155.250. Scott Co Sheriff was on 37.10 & 37.16. They used 37.10 when they needed to talk to units north of Parkview along the Wapsi. Most of Eastern Iowa Counties were using 37.100 including Clinton PD that used voice inversion scrambling. By then the state was moving the Patrol to high band VHF. The state techs designed a frequency layout for the state in the 37.10s so the counties used 37.100 as common and another frequency for dispatch. Sometimes Davenport and Scott Co would patch their dispatches together for major incidents.
Cedar Rapids PD had just switched to UHF from several 39.xxx channels.
When the state set the VHF high plan there were changes due to frequencies being used in bordering states. Clinton Co was assigned 154.845 and 155.535. But 154.845 was already used by the Illinois State Police district in Rock Island and 155.535 was used by Jo Daviess County IL. so they were replaced by 154.965 and 155.520.

So let me make sure I know what you're saying. So in 1976, many counties in your part of the state were using 37.1 for their regular dispatch. But shortly thereafter, the state designed a frequency layout that changed the use of that frequency from regular dispatch to a common channel (did it have a name?), similar to point-to-point 155.370 today (well in the recent past, since a lot of what would be point-point traffic is now on ISICS). And the regular dispatch frequency had to change, since 37.1 was turned into the common channel.

Do I have that about right?

 

[radioboy75]

Hey! I found something very helpful! This is the Iowa Law Enforcement Telecommunications Plan from 1974! (picture attached) The full document can be found at https://www.ojp.gov/pdffiles1/Digitization/48504NCJRS.pdf. I was just Googling the wrong terms I guess. Found this with search terms: "iowa highway patrol" 42 MHz. And with that I was able to come up with all kinds of knowledge that wasn't even about the IHP . . .

 

[lenk911]

The big change in police radio occurred in the early 1970s when congress passed the Law Enforcement Assistance Act (LEAA). Congress appropriated about 6 billion dollars to grant to the states to improve police radio systems. Each state had to develop plan that included a common mutual aid channel generally in the VHF band. Most states organized around 155.475 MHZ but many used a different frequency such as Illinois and Texas. The plan had to be filed with the FCC. Each state hired a consulting firm to develop the plan and they and the state's radio board managed the bidding and construction of the new systems. The grant paid 80% of the system cost and the locals matched with their 20%.

Many State Patrols, like Illinois and Minnesota couldn't fund a statewide switch from 42 MHZ to VHF. They purchased second radios with red microphones for each trooper squad tuned specifically to the mutual aid channel. There weren't enough VHF channels in the band for the larger cities so they opted for the UHF band but were supposed to have patching back to the statewide mutual aid channel.

In Iowa, that forced the change from low band to VHF. I recall the main Iowa consultant was Warren Amphar (?) a long time employee of Collins Radio. Through the plan and the consultant they built the system we knew up to the present 700 MHZ system was constructed.

Prior to 1970, It was tough communicating cross border between Minnesota and Iowa. Almost all Minnesota counties were on the VHF band and of course Iowa counties used 37.10. Rochester Highway Patrol Dispatch crossed channeled with Belmond Patrol Dispatch was about all we had.