POLICE SCANNERS?

[AIRMAN]

Why is it that some countries call than 'Police' scanners? The media tend to call them that as well. I asked a journo I know and he reckons it originates from the USA, or, it could be used to differentiate document scanners or flat bed scanners from scanning radio receivers.

Frequencies used by Police in urban areas may soon be encrypted, many are already. So what's next? Fire scanners?

[bodyguard]

Monitoring police communications goes back to the early 1930's when police broadcast were done through local AM radio stations. Field units would monitor the radio for calls and anyone with a radio would also hear the broadcast. For a detailed overview of how this all worked, check out this page. It is also helpful to read Harry Marnell's "LAPD Communications Division History." Jump forward to the early 70's.

Crystal-Controlled Scanners

In a conventional radio system, a frequency is used for each channel of communication. To hear transmissions for what you want to listen to, you must have the specific frequency for that channel programmed into your scanner. For example, a local police department’s dispatch channel would be on one frequency and their car-to-car channel would be on another separate frequency.

The first generation police scanners were crystal-controlled conventional scanners, with 4 or more channels. To monitor a particular frequency, you had to have a quartz-crystal tuned to that frequency and plugged into one of the scanner's internal slots (one for each channel). Each crystal cost around $7.00 and got a little expensive once 16 and 20-channel scanners came out. Crystal-controlled scanners can still be found in yard sales and even on ebay.

Programmable Scanners

In the late 70's, programmable scanners were introduced and it was heaven! NO MORE CRYSTALS! These new scanners came with a keypad that allowed you to directly enter frequencies into the scanner's memory (one per channel) just as today's scanners do!

thanks to
www.police-scanner.info for the above info

[AIRMAN]

Very interesting post. Thanks BG

[Stretch]

Yeah nice post BG

I've always referred to them as radio scanners. Nice topic Airman

[Comint]

Why is it that some countries call than 'Police' scanners? The media tend to call them that as well.

Probably because thats all most people use them for.

or, it could be used to differentiate document scannersor flat bed scanners from scanning radio receivers.

Radio scanners predate document or flat bed scanners by many years.

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Comint

[Comint]

I've never liked the term "scanner" for a receiver, I prefer to call them "communication receivers".

The term 'scanner' comes from the fact that the receiver 'scans' across a number of channels, rather than just sitting on one channel.

And Icom called their scanners "communications receivers" to get around a copyright problem.

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Comint

Edit: Changed law to problem.

[Stretch]

And Icom called their scanners "communications receivers" to get around a copyright law.

What law???

[Comint]

And Icom called their scanners "communications receivers" to get around a copyright law.

What law???

"Law" may have been the wrong word to use, but apparently one of the major scanner manufacturers copyrighted the term "radio scanner" some years back, so any other manufacturer using that term since that time is in breach of copyright, unless, of course, they pay "Royalties" to the copyright holder.

I guess Icom didn't want to have to pay Royalties.

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Comint

[AIRMAN]

I guess Icom didn't want to have to pay Royalties.

Neither did AOR.

[Stretch]

Thats harsh. Don't see how a company should be able to copyright something like that. Mind you, I have seen it in the past.