When Did The 88-108 FM Band Become The Norm ?

[camtechman]

I'm trying to date a radio with AM & FM bands. When was the 88-108 FM introduced as the norm, was it c1972 ?

[colly0410]

I've got a couple of radios that only go up to 104FM so would be interested to know.

[JayBee66]

I have a Teleton GT-202 tuner from the mid 70s that only goes up to 104.

Also, I have a Philips B5S12A from 1961 that only goes up to 100.

[camtechman]

I do remember the BBC sending out a pack of stickers to apply to those with VHF/FM radios. It contained one larger sticker that listed the main BBC radio stations & frequencies and a smaller strip of diamond shaped stickers that were intended to be applied to the FM tuning scale to show each station. I think that was around 1972-74.

I'll have to dig out a pack of unused stickers as it may have a date on it, although, at present, I know I have them but where I've put them, goodness only knows !

[camtechman]

It seems I forgot that it was done in stages and thanks to Wikipedia I found this info for the UK transition:

"Only when commercial broadcasting was introduced to the UK in 1973 did the use of FM pick up in Britain. With the gradual clearance of other users (notably Public Services such as police, fire and ambulance) and the extension of the FM band to 108.0 MHz between 1980 and 1995.

When the BBC's radio networks were renamed Radio 2, Radio 3 and Radio 4 respectively in 1967 to coincide with the launch of Radio 1, the new station was the only one of the main four to not have an FM frequency allocated, which was the case for 21 years.

Instead, Radio 1 shared airtime with Radio 2 FM, on Saturday afternoons, Sunday evenings, weekday evenings (10pm to midnight) and Bank Holidays. Eventually in1987 a frequency range of 97.6-99.8 MHz was allocated as police relay transmitters were moved from the 100 MHz frequency, starting in London before being broadly completed by 1989"

[Cobaltblue]

Unfortunately hard to date sets by the VHF coverage since they were many sets that covered to 108MHz earlier such as the 1960 Perdio PR95

Cheers

Mike T

[julie_m]

I would guess later than 1972. I had a 1973 / 74 ITT KB radio that only tuned up to 104 MHz. BBC Radio Derby moved from 96.5 to 104.5 sometime in the late 1980s, and became inaccessible to some older sets.

[Radio Tech]

Makes me wonder if manufactures done this for a purpose due to the fact at one stage you could listen to the emergency services and taxis on those sets, and certainly if a TV had built in radio, the services and aircraft could be easily heard. Not so easy now though they are using frequencies up to microwave

Ken

[Radio Wrangler]

It was a lot more complicated than that!

There had been a gentlemen's agreement to only have low power stuff in the 100-108MHz band so that aircraft navigation and landing aid receivers weren't tenderised by having high power broadcasters immediately adjacent to them. So the aviation world had to re-equip with dramatically hardened receivers with added filters before broadcasters could move into that band.

In an amazingly bad bit of frequency planning that just sort of happened for historical reasons, the very worst combination of neighbours has happened. Broadcasters up to 107.9MHz and automatic landing system beams on 108.1MHz and upwards.

Aircraft receivers have to give correct navigational indications with signals down to -86dBm with neighbouring broadcasts up to +15dBm. Ouch!

A lot had to change in the aviation world to avoid the move causing disasters.

David

[Paul_RK]

Yes, it wasn't until around 1980 that tuning to 108 MHz was fairly universally provided. Hacker sets, for instance, were being made and new models introduced until 1979-80, but none of them extends beyond 104 MHz except their first FM model of all, the RV14 Mayflower. Could be worth telling us the radio you want to date, someone here may have evidence for exactly when it was released.

Paul

[Synchrodyne]

The basis for extension of Band II to 87.5 to 108 MHz in Region 1 was included in the ITU 1984 Geneva meeting, and evidently stemmed from an agreement made at the WARC 1979 meeting. No doubt implementation took several years and proceeded at different speeds in different territories. The ITU document did refer to the need to protect from interference the Areonautical Radionavigation service operating just above 108 MHz. See: http://www.ancom.org.ro/uploads/link...eneva_1984.pdf.

Although I imagine that the potential aeronautical interference problem had arisen and had been solved in North America, where the 88 to 108 MHz FM Band was established in 1945.

The use of 100 to 104 MHz for FM broadcasting in certain European countries was covered at the ITU 1959 Geneva meeting. At that time, Band II in Region I was still 87.5 to 100 MHz. See: http://www.itu.int/dms_pub/itu-s/oth...85201PDFE.PDF; page 64, footnote #270.

An observation is that amongst the European equipment makers, from quite an early stage, their hi-fi FM tuners, no doubt with export markets in mind, usually covered 87.5 to 108 MHz (or even 87 to 108 MHz, bearing in mind that in Region 3, Band II covered this range). On the other hand, domestic receivers often had an upper limit of 100 or 104 MHz. One would expect that, after WARC 1979, or at least after ITU 1984, that the setmakers would have planned for coverage to 108 MHz.


Cheers,

[paulsherwin]

The Home Office took a very long time to move the police and other emergency services out of the FM broadcast band, because of delays and technical difficulties with the replacement systems. I think the frequencies were finally freed up in 1986 or 87, allowing the introduction of the BBC R1 FM transmitter network and later the launch of Classic FM.

[Biggles]

I was involved with re-engineering the VHF emergency services in Cumbria at the time of the WARC changes and it was about 1986. They were moved up to VHF high band and the site links were moved from high band to a microwave frequency at the same time. Radio One probably arrived on FM about a couple of years later if I remember correctly. Previously we used to experience interference on our low band main site receivers from FM broadcast transmitters so it solved a few problems in one go.

[crackle]

There were some earlier exceptions, but it seems that my collection of ITT radios all seem to cover the full FM range of around 88 to 108 MHz from about 1979. An example is the ITT Weekend Stereo Cassette 110.
One of the exceptions and the earliest full range FM radio I have is the 1964 KB KR016 "International". I can remember regularly listening to the "Police" on one of these Radios back in the 60's.

Mike

[Hartley118]

Originally Posted by Paul_RK

Yes, it wasn't until around 1980 that tuning to 108 MHz was fairly universally provided. Hacker sets, for instance, were being made and new models introduced until 1979-80, but none of them extends beyond 104 MHz except their first FM model of all, the RV14 Mayflower. Could be worth telling us the radio you want to date, someone here may have evidence for exactly when it was released.

As Paul says, whilst FM band range might seem a sensible way of dating a set, it's complicated and unreliable. For example in answer to your question, I immediately plumped for the date 1962 because my Mark 1 Hacker Mayflower has the full range up to 108 MHz. Then I noted that the later 1963 Mark 2 Mayflower only goes as far as 104 MHz because it uses a different tuner front end. So the tuning range is more an indicator of the RF module type than date of the set.

Martin

[KeithsTV]

My 1974 ITT Europa 100 is marked up to 104MHz and the car radio I bought in 1983 also only went up to 104MHz. I think it was the late 80s when the band up to 108MHz started to be used for broadcasting.

Keith

[julie_m]

Certainly it was in the late 1980s that local stations were freed-up from the requirement to simulcast their programmes on MW and FM -- the station that used to have been Trent 945 became Trent FM, carrying on playing the latest hits but only on the VHF-FM band; and the old 945 kHz frequency became Gem AM, now playing oldies and syndicated across the MW frequencies that used to belong to Nottingham Trent and Leicester Sound.

[emeritus]

The first FM portable I bought was a very cheap Hong Kong model and that went up to 108MHz. It would have been around 1973, and would I suppose have been made with the US market in mind. The front end selectivity/alignment/design was so poor that it was possible to receive television sound from all three channels sufficiently clearly that I bought one for an uncle who was hard of hearing so he could use it with headphones when watching TV: TVs of that era generally did not have headphone sockets.

The tuner of the Alba UA 700/800 combination goes up to 108MHz. Its design probably dates from the mid 1970's as I bought mine when Laskeys was selling them off circa 1978. The stereo FM tuner (Lindsey-Hood?) that I built from the design published in "Wireless World" in the mid-1970's also goes up to 108MHz.

[Rhgbristol]

The BBC-supplied stickers were issued in the late summer and autumn of 1978 to pre-empt the wavelength changes of November that year.

From memory however, the wavelength changes at that time mainly affected AM band and were I believe,

Radio 2 long wave becoming radio 4 on 1500m
Radio 1 moving from 247m to 275 and 285m
Radio 3 going from 464m to 247m
And some others I can't remember!

I think the stickers were posted to all addresses - or may have come with Radio Times magazine.

There was a square sticker of about 30mm square that listed the frequencies and small red and blue diamond shaped marker stickers to stick on the tuning dial.

The stickers were very thin plastic, but stuck very well - and can often be seen stuck on old radios to this day some 38 years later !

[Rhgbristol]

Regarding the FM bandwidth allocations, these were some years after the 1978 AM re-allocations from what I can remember.

Certainly as late as the early 1980s I can remember 'listening in' unofficially on the police and ambulance services who could be heard below 89MHz and above 100MHz.

Radio 1 got its full time allocation to FM in 1988, and this corresponded to the station's jingles and self-made references to 'One FM'. There was also a car window sticker in 1988 encouraging Radio one listeners to switch to FM - with the wording 'Radio 1 -FM - A sound move'.


It was the advent of the commercial radio stations explosion in the early 1990s onwards that heralded the use of these extremities of the FM band II for commercial broadcasting.

Here in Bristol we had Classic FM appearing in 1991 on 101.7MHz and afterwards other local stations like Jack FM up on 106.5MHz.

Speaking with aerial manufacturers like Antiference and our local Bristol company Telefield in the early 1990s, revealed that rightfully they were altering the dimensions of the half wave dipole FM aerials to be better optimised to the increased frequency band.

The pre 1990 aerials were generally sized to an average frequency of 95MHz with the corresponding half wave dipole dimensions, where as the post 1990 aerials had slightly smaller dipoles better optimised to an average frequency of about 99 MHz.