Police radio in the UK on the FM band before Radio 1?

tinytobe

Just wondering back when BBC Radio 1 was on AM, could one receive police radio on the FM band in the UK?

Apparently, the frequency range between 97 and 99 was used for police radio until the late 1980ies?

Some older people say that that's true. However I still find it hard to believe.

TheBMG

https://www.boards.ie/discussion/2058283325/police-radio-in-the-uk-on-the-fm-band-before-radio-1

Yup. It was also possible to hear utility services and taxi companies down below 88mhz

Glaceon

https://www.boards.ie/discussion/comment/120213714#Comment_120213714

Still is to an extent. I hooked up a HackRF to an FM radio aerial a couple of years ago and could hear taxis around 83 MHz.

Ger Roe

Listening lower than 88mhz could usually be done by tweaking the tuning capacitor on a standard FM radio, by a few turns.

In the late 70's to early 1980's I could hear Northern Ireland police on FM (somewhere up above 100Mhz) from my high reception point in Sandyford. Considering what was going on at the time 'up north', I though it very strange that they could be heard on a standard receiver. I once heard a police car sign off for the night by calling up its station and then saying 'goodnight listeners ... everywhere'.

dxhound2005

There is supposed to be an urban legend where police exchanged radio messages about a UFO having landed at a particular location. When the listeners turned up to have a look, they were arrested.

Comreg allocates 75.2 to 87.5 MHz to:

VHF Low Band: Land Mobile PMR, Community Repeaters and Third Party Business Radio.

Infoanon

When the original Radio Nova switched off its 88FM transmitter, after a few days it's news included a piece asking other radio stations not to use 88FM as Dublin Gas iirc had been allocated the frequency.

Radio Annabel has jumped on the frequency iirc.

As for the UFO story - probably urban legend but there was some oddity about it being illegal to listen to the police broadcasts.

A true story - UK land pirates became aware of the frequency the DTI pirate raiders were using to communicate before a raid and for a short while TX loses were avoided much to the bemusement of the DTI officials.

tinytobe

https://www.boards.ie/discussion/comment/120214966#Comment_120214966

Thanks for that one. I've heard similar stories about that being also the case in the rest of the UK. These stories are often mentioned in connection with BBC Radio 1 gradually moving or moving to FM, between 97 and 99.

I think it's a bit of a strange one considering that one would have been able to buy radios covering 87,5 to 108.0 even back then. So apparently anybody could have listened to the police on a regular radio?

Antenna

THe Original Poster had already raised this issue within the thread linked below, which led to what I though were good, accurate, and some very lengthy posts in reply (which must have taken up considerable time to go to the effort to type up by Tafkalawhec ):

https://www.boards.ie/discussion/2058270377/question-about-the-clermont-carn-transmitter

tinytobe

https://www.boards.ie/discussion/comment/120218837#Comment_120218837

Thanks. Sorry, and yes the subject comes up every now and then.

It's just still surprising today. Did the authorities never have any concerns. Was it legal to listen and to tell others what one heard?

Ger Roe

https://www.boards.ie/discussion/comment/120218868#Comment_120218868

My understanding was.... the fact that the signals were not encrypted means that they were known to be open to being heard by anyone who had the equipment to do so. If you bought or made a receiver that covered the specific frequency concerned, then you could obviously hear what was said. Legally, however you were under an obligation not to disclose or use the information obtained.

There was (is?) a slightly similar obligation with amateur radio operation, where you could obviously communicate with other people, but you could not pass on messages intended for a third party, as that would deny potential revenue for the postal or telecomms service. If someone that you contacted in New York asked you to call around to the Murphys down the road and let them know you were talking to their cousin John and all was well with him.... you were prohibited from doing so. John had to write to them, or ring them himself, using the services of the department of posts and telegraphs.

Just before the Gardaí changed to the encrypted system, it was not unusual to hear either a car or a station ask their called party to 'ring on the mobile'... obviously well aware that scanners were freely available in various radio equipment shops around Dublin. While you needed a bit of knowledge to programme and operate a scanner, the fact was that the signals were essentially 'free to air' and available to be listened to.... you can't legally exclude sections of the radio spectrum from being received.

tinytobe

https://www.boards.ie/discussion/comment/120219728#Comment_120219728

Thanks for your answer. What I simply don't understand is why did the police in the UK chose a frequency around 100 Mhz?.

Even in the 70ies or early 80ies one could have bought a simple FM / AM radio which would have gone from 87,6 to 108 Mhz. Most Japanese models did cover that frequency range, Sony certainly did. Some German radios only went up to 105 Mhz, as far as I know.

I would have expected the police to be "a bit smarter" than to chose a frequency which anybody could receive. And I am not talking about scanners, but normal radios.

dxhound2005

That could be like asking why did the royal family build Windsor Castle so close to Heathrow. Without looking it up I presume the police were there first, and an extended process had to be followed to move them when the broadcasters were allocated the band.

tinytobe

https://www.boards.ie/discussion/comment/120223779#Comment_120223779

You do have a point there, but neither in Germany, Switzerland or in France did the police use this frequency range.

Did the Irish Guards also use any part of the 87,5 to 108 spectrum for their communication?

Also it would have been very easy to use a different frequency ? And moving Windsor Castle or Heathrow airport isn't that easy as moving to another frequency range.

dxhound2005

"Frequency utilisation

From 1955 the band 88.0 – 94.6 MHz was used (allotted and assigned) for three BBC national networks. Over the next 40 years, the band grew piecemeal to 87.5 – 108.0 MHz, allowing for five national networks and many local stations.

Until 1995, parts of the band had been used in the United Kingdom for mobile service by police, fire brigades and the fuel and power industries. These parts were reassigned to broadcasting service gradually over many years as the communications services were transferred to new equipment in other parts of the spectrum."

"FM sound broadcasting began in the United Kingdom on 2 May 1955 when the BBC started an FM broadcasting service the Light Programme, the Third Programme and the Home Service to the south east of England."

Glaceon

https://www.boards.ie/discussion/comment/120223684#Comment_120223684

My dad had a Pye stereo system that only went up to 104.

rathfarnhamlad

I had a Hacker VHF-only portable, must have been post-1967 but not much newer than that. It only went up to 100 MHz. I have also seen valve/tube radios that featured VHF but similarly only up to 100.