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#1
11-13-2019, 01:27 AM
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In the UK, Channel 4 started in 1982. It was rolled out nationally over a short timescale. The UHF channels had been assigned as part of thejoint BBC/ITV band planning process which gave 4 channels to each transmitter. The aim was to achieve full national coverage (99% of population?). Channel 5 was shoehorned in much later. A bit of a bodge job, with large areas not covered.
The 405 line services in Bands I and III (Low and High band VHF) were finally tuned off in 1985. These bands have not been used for TV since then. There are still a surprising number of antennas visible. 
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#2
08-13-2020, 07:26 AM
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In the early 1970's my parents bought a Sony KV1800: It only had a UHF rotary tuner (which were very unusual on English sets) but there was a square blanking plate just below where I presume a VHF tuner would have gone if it went anywhere else in the world but England. Most English made single standard 625 kines sets back then had push button UHF only tuners with 4 buttons that could tune to any UHF broadcast channel, they were marked from top to bottom: BBC1, BBC2, ITV & the fourth button would on some sets say ITV2, (there never was an ITV2 back then, there is now though) & some with just a * on it. People living in ITV overlap areas could receive an alternative ITV station & this was tuned in on button 4. When channel 4 (channel 4 was the station name not the broadcast channel, it was broadcast from hundreds of transmitters on nearly all UHF channels) fired up in 1982 that was then tuned to button 4, people who had previously tuned it to another ITV TX were then chockered. Later sets had 6 or 8 buttons on their tuners, then came remote controls...
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#3
04-22-2021, 05:55 AM
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For those that are interested in UK/European UHF Antennas/Aerials.
I just had my UHF TV aerial changed, there was water in the cable. it was one like the one below. It was wideband channels 21-68. The new one is a log periodic UHF 21-60 like the one below. I live about 25 miles from the Sutton Coldfield transmitter. Each multiplex is output at 200kw, both new and old require a mast top amplifier and power supply in the house. Interestingly, modern aerials use F-Connectors (like satellite TV) and not traditional aerial plugs or hard wired. The old one was on a 10ft pole - the new one a less rattly 6ft... Needless to say i get all eight Freeview Multiplex’s perfectly, almost £200 down... oh well. Patrick North Worcestershire, UK
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#4
04-23-2021, 12:48 AM
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Hi Patrick. That's a nice looking log periodic.
Since this is mainly a left-pondian forum the subject of aerial connectors may need a bit of explaining. Most of the world including the USA has used F connectors for aerials for many years. It's really only the UK that has kept the traditional Belling-Lee co-ax connector. To a lesser extent it's used in the rest of Europe. https://en.wikipedia.org/wiki/Belling-Lee_connector The F connector is a much better connector. Better screening, better return loss. Easier to wire too. Though you do need the correct size conenctor for the cable and the simple versions only work with solid core co-ax.
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#5
04-23-2021, 09:36 AM
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Quote:
The antenna on the right looks exactly like a Blonder Tongue design  , which is an expensive one in the US due it's commercial-duty market. I have yet to find or try one of them. Since the US has retained all the previous VHF and only the UHF channels 14-36, former UHF designs (ch. 14-69) could all use some tweaks now.The US has many areas that are extremely difficult to cover with UHF, VHF was retained because it is less affected by trees, hills, etc.
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"When resistors increase in value, they're worthless" -Dave G Last edited by DavGoodlin; 04-23-2021 at 09:42 AM.
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#6
04-23-2021, 03:12 AM
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The UK traditional aerial plug and socket is actually used in the vast majority of countries around the world on TV sets - its often called a PAL connector, but was also used in SECAM countries. The main exceptions to this rule is ex NTSC and North/South American countries where they use the F-Connector.
France actually had a similar slightly smaller plug on their early TVs but changed to the Bulgin Lee type, I suspect in the seventies. The Germans had a special two pin plug. Some Japanese portable sets, had either screw connectors or 3.5mm pin socket similar to a headphone socket today. Over the years I have looked on the net at the aerial connectors on TVs all over the place, most countries in the fifties, sixties and early seventies used 300ohm flat cables with screw connectors, then converted. We had a 1955 Philips 405 line TV which had a UK Coaxial standard aerial socket, so I think the British may have been forerunners in using coaxial aerial cables on TV sets. Coaxial Cable of course helps prevent break in interference. As you say, the F-Connector is more secure and better suited for satellite and aerial cables with a copper core and copper braid/sheath along its length. My first device with an F-connector, here in the UK was a Sony ST-3950 Stereo Tuner, I bought it in 1979, a beautiful device. It was supplied with a plug that required a crimp tool to fit. F-Connectors were of course used from the late eighties in Europe on Satellite TV, so F-Connectors are everywhere now, but TV sets outside ex-NTSC countries still use the UK type plug.
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#7
04-23-2021, 10:41 AM
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The one on the left, lasted me about 25 years (mine didn't have much plastic) but was attached to a high chimney and used to rattle. If it hadn’t been for the cable I think it would probably still work now. The aerial fitter disuaded me from having one of the fan type (like below) UHF arrays for the reason you mention, they tend to fall apart.
I will never understand why the UK didnt re-use VHF for TV after 405 line was switched off in 1985. I think we must have been the only country in the world to have TVs with UHF only tuners. Simple for tuning of course, but it meant portable TVs rarely worked properly without a rooftop aerial. Kinda missing the point, even so Casio sold loads of portable handhelds in the UK, just look on the ‘bay. Of course we now have DVB-T and T2 digital TV which means most folk can receive 70 odd channels, not the previous 5. Plus free to air satellite with even more and we have the internet for portable devices..
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#8
07-07-2021, 12:48 PM
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The vast majority of TV's sold in Britain after 1970 were only fitted with a UHF tuner, I'm presuming that we were the only country in the world that did this. You'd see the odd one with a VHF tuner, I'm presuming that this was so they could be sold in Ireland or other system I countries that used VHF...
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#9
07-07-2021, 05:39 PM
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In Spain they where also U.H.F. only.
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#10
12-04-2022, 06:40 AM
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When UHF became de facto normal here in UK there were lots of areas that had poor reception compared to VHF, so they built many relay stations: These would usually be on a hill or high ground & receive a signal from a main station & re-transmit it on another channel, usually with vertical polarisation to reduce co-channel interference. In some mountainous areas they'd have relay stations relaying another relay station. There were a few places where they'd have a daisy chain of relay stations relaying one after another, what/where the longest daisy chain was I don't know...
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#11
12-04-2022, 07:31 AM
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Circular polarization is supposed to overcome those obstacles. CP came out in the 80's here. Many stations adopted it. It required the addition of a second transmitter. So those stations had double ERP.
https://www.tvtechnology.com/opinion...r-polarization
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#12
12-12-2022, 02:20 PM
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I am pretty sure everyone has seen the film Fahrenheit 451.
https://en.wikipedia.org/wiki/Fahrenheit_451_(1966_film) During the opening credits that are spoken, images of UHF and a few VHF antennas are seen...
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#13
12-13-2022, 03:48 AM
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I don't know how things work on that side of the pond but UHF will never measure up to VHF for the raw coverage and penetration in the real world. I'm small town USA and ever since we went DTV and the b'cast went UHF it's been a challenge for reception. We have a few sub-channels running on ch-9 (186 MHz) that I can pick up with my amateur 2M Ringo but UHF is a little difficult despite their sub-megawatt ERP and 1470 AGL towers.
I applaud the forward thinking engineers who developed the PAL standard and 625 line system as it is far superior to our NTSC in many ways however I've always questioned the wisdom behind going exclusive UHF.
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