History of Bands

[Thatsclear]

In general, was the first band used 39 Mhz for public safety? Then it went to VHF, then UHF, then 800 MHz and now 700 MHz? Does anyone have any years about when these changes occurred? Thank you.

 

[kb9mwr]

One would have to take into account state/county budgets. California and New York due to the population density and lack of room on a specific band would have likely been the first to migrate to other bands. Your best bet would to look at old issues of Popular Communications and Monitoring Times magazines.

 

[doctordialtone]

In general, was the first band used 39 Mhz for public safety?

I used to have an AM Radio that had "Police" on the dial above the 1600 label.

AM expanded band - Wikipedia

en.wikipedia.org

Read the Region 2 section.

 

[MStep]

In general, was the first band used 39 Mhz for public safety? Then it went to VHF, then UHF, then 800 MHz and now 700 MHz? Does anyone have any years about when these changes occurred? Thank you.

'
doctordialtone just beat me to it whilst I was replying, but to expand, my very vague recollection is that during the 1940's and early 1950's, some agencies were using frequencies directly above the AM broadcast band in the 2 MHz range for one-way transmissions to mobile units. My interest in monitoring first became spurred when studying the dial on grandma's AM broadcast receiver. In addition to the traditional "CD" (Civil Defense) markers imprinted on the dial panel, the word "Police" appeared following the 1600 KHz frequency marker.

I did hear some transmissions, but they were spotty and not local to my area. And thus, at 4 or 5 years old, my interest in the hobby began.

 

[RFI-EMI-GUY]

The 800 MHz band development rolled out in the Late 70's and marketed in early 80's. UHF, I am guessing mid 1960's. GMRS or Class A CB was in the 460 band much earlier, 1950's perhaps.

 

[chrismol1]

Besides the 20's when they started with one way comms in the am broadcast band. Two way began a little after that in VHF Low in the early 30's. Here is some cool historical documents from the FCC. They talk of allocating some VHF High freq for police in 1939
Radio History Documents

 

[nd5y]

https://worldradiohistory.com/Archive-FM-Magazine/FM-1949-07.pdf contains a directory of FCC licenses (what would be called public safety today) as of July 1, 1949.

FM - TELEVISION MAGAZINE - An early journal about the new FM and TV services

FM & Television Magazine offers an interesting view of early FM, including articles about the early FM Association in 1947 and the equipment and engineering aspects of the band

worldradiohistory.com

Some of the other issues also have them. 1949 was the earliest I could find.

 

[ko6jw_2]

The contention that there has been a move to higher frequencies is a generalization which is only partially true. I remember up to the late "60's hearing LAPD on MW. I could hear them at night 100 miles away. The LAFD had a large number of channels in the 33MHz range until the late '70's. The California Highway Patrol still uses 39-45 MHz with most activity at 42MHz. Why? Propagation. Low band gives superior coverage in many cases. When the Santa Barbara County Sheriff moved to UHF from low band coverage was poor and they had to have many more repeaters. Of course 700 and 800 offer trunking and digital that would not have the spectrum availability on VHF. There are exceptions. Alaska has a VHF trunked system outside of Anchorage. LAFD uses 800MHz but is not trunked. Much of fire systems in California are VHF. Local fire departments are still on same dispatch frequencies they have used since the early 1950's. They have many more channels and repeaters but are not moving to UHF anytime soon or at all.

 

[GlobalNorth]

1.6 to 1.8 MHz was the initial public safety band. There was a single transmitter at a station and the cars had receivers.