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Old 01-08-2017, 01:46 PM
Colly0410 Colly0410 is offline
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British use of high band.

High band (band 3) in Britain is channels 6 to 13. ITV started in late 1955 on channel 9 broadcasting from Croydon to the London area. Then in 1956 Litchfield (near Birmingham) on ch 8 fired up for the English midlands, Winter Hill ch 9 for north west England & Emley Moor ch 10 for Yorkshire. Then in the late 1950's Black Hill fired up on ch 10 for central Scotland, Chillerton Down on ch 11 for Southern England, St Hillery ch 10 for South Wales/West of England, Black Mountain ch 9 for Northern Ireland, Mendalsham ch 11 for East England, Burnhope ch 8 for north east England, Caldbeck ch11 for Borders area, plus others. Channels 6,7,12 & 13 were not used till the early/mid 1960's so there was a lot of channel reuse of 8,9,10 & 11. In 1964 (I think) the BBC started to use High band as low band was saturated, 1'st BBC high band was Winter Hill ch 12 for north west England, Wenvoe ch 13 for South wales, Belmont ch 13 for Lincolnshire, Caldbeck ch 6 for south east Scotland, Moel-Y-Parc ch 6 for north Wales...

High band is now used for digital radio using DAB & DAB+ systems...
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Old 01-08-2017, 05:50 PM
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Quote:
Originally Posted by Colly0410 View Post
...

High band is now used for digital radio using DAB & DAB+ systems...
Last week I picked up at a Goodwill thrift shop a Colourstream Internet, DAB and analog FM receiver. Took a while to convince it to use the wired ethernet connection for Internet access, but it works well now for Internet streaming and analog FM reception. Of course, here in New Jersey, USA it doesn't hear anything on DAB mode. According to the specs, this DAB band runs from 174 to around 230MHz, which is mostly our channels 7 thru 13 and then a little more. I suppose it is possible to have a few DAB transmitters using empty TV channels here, but I doubt that would ever happen.

This receiver requires 230VAC but we do have 250VAC (a pair of 120VAC's) here in the USA, though at 60Hz. This radio is happy on 60Hz, even though it states 50Hz. Aside from record players and clocks, transformers are very happy on 60Hz even though they are rated for 50Hz.
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Old 01-09-2017, 06:03 AM
Colly0410 Colly0410 is offline
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The BBC transmit digital radio as a single frequency network on ch 12B (225.648 MHz) from hundreds of transmitters all over the country, there are stations on digital you you cant get on AM or FM. All BBC & most commercial national radio stations are also carried on the Digital TV transmitters as sub-channels. (all TV is at UHF) I have audio leads from my Freeview+ digital-box to my hi-fi for fantastic quality music on the oldies stations...
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Old 01-09-2017, 10:31 AM
dieseljeep dieseljeep is offline
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Originally Posted by Colly0410 View Post
High band (band 3) in Britain is channels 6 to 13. ITV started in late 1955 on channel 9 broadcasting from Croydon to the London area. Then in 1956 Litchfield (near Birmingham) on ch 8 fired up for the English midlands, Winter Hill ch 9 for north west England & Emley Moor ch 10 for Yorkshire. Then in the late 1950's Black Hill fired up on ch 10 for central Scotland, Chillerton Down on ch 11 for Southern England, St Hillery ch 10 for South Wales/West of England, Black Mountain ch 9 for Northern Ireland, Mendalsham ch 11 for East England, Burnhope ch 8 for north east England, Caldbeck ch11 for Borders area, plus others. Channels 6,7,12 & 13 were not used till the early/mid 1960's so there was a lot of channel reuse of 8,9,10 & 11. In 1964 (I think) the BBC started to use High band as low band was saturated, 1'st BBC high band was Winter Hill ch 12 for north west England, Wenvoe ch 13 for South wales, Belmont ch 13 for Lincolnshire, Caldbeck ch 6 for south east Scotland, Moel-Y-Parc ch 6 for north Wales...

High band is now used for digital radio using DAB & DAB+ systems...
How did the British high band compare with the NTSC high band, channels 7-13? In the US, channel 6 was part of the low band. There was a lot of space between channels 6 & 7.
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Old 01-09-2017, 12:43 PM
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The BBC transmit digital radio as a single frequency network on ch 12B (225.648 MHz) ...
In the USA we hams have a band from 222 to 225MHz, and another at 219-220 MHz as secondary use. But you have a band at 70MHz, which we don't.
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Old 01-13-2017, 08:15 AM
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Robert Grant Robert Grant is offline
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British monochrome analog television used only 405 scanning lines and only 25 frames per second, resulting in only 10,125 lines transmitted per second (compared with 15,750 or 15,734.2xx per second for USA analog television). This meant that the British system only needed 5MHz for a television channel instead of America's 6MHz, and yet had more horizontal resolution than American television

This allowed the UK to place eight highband channels 6 through 13 in Band III with two MHz left over.

Note that Britain's five Band I channels ended at 68MHz and that they never had Band II over-the-air television at all.

Unusual about UK television is that it has been through not one, but two, incompatible transitions.

From 1964 to 1985, they had the 405-line VHF to 625 line UHF transition, including television sets in the UK that were dual standard sets, which switched from positive modulation 405-line video with AM audio and -3.5 MHz audio offset, to negative modulation 625-line video with FM audio and +6MHz offset when the user switched from VHF (BBC1 and ITV) to UHF (BBC2).

From November 1969, UHF 625 line transmissions of BBC1 and ITV were added, so television sets made from about 1970 onward had no 405, positive picture detection, AM audio, nor VHF tuner.

The second transition was done like everywhere else in the world. UHF Digital transmitters were shoehorned among UHF analog transmitters with the latter shut down years later and some improvements made to the digital transmitters later.

Last edited by Robert Grant; 01-13-2017 at 09:40 AM.
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Old 01-13-2017, 09:45 AM
Colly0410 Colly0410 is offline
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From 1964 to 1985, they had the 405-line VHF to 625 line UHF transition, including television sets in the UK that were dual standard sets that switched from positive modulation with AM audio and -3.5 MHz audio offset with 405 lines to negative modulation with FM audio and +6MHz offset with 625 lines when the user switched from VHF (BBC1 and ITV) to UHF (BBC2).

From November 1969, UHF 625 line transmissions of BBC1 and ITV were added, so tellies from 1970 on, so tellies from 1970 onward had no 405, positive picture detection, AM audio, nor VHF tuner.
Some dual standard sets were still being used into the 1980's, they were so complicated though that they were scraped as they were too difficult to mend when they went wrong. I've got a 625 lines UHF only set from 1971 that still works when fed from a digital box UHF RF output.

The last 405 lines VHF only sets were sold in 1968/9, 5/6 years after 625 started, mind you the 405 lines VHF transmitters carried on broadcasting till the 1980's, the last ones shutting down on 31 Jan 1985, but almost everyone was then on 625 lines colour at UHF & no one noticed, there's a you tube video of it. Colour was never broadcast on 405 VHF. BBC2 fired up with colour in 1967 on 625 UHF, & BBC1 & ITV fired up in colour in November 1969, also on 625 UHF. All Antenna TV is now digital at UHF only..
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Old 01-14-2017, 02:53 PM
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Thanx for this interesting news report!

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Scotty, beam me up, there is no more 4/3 Television and AM radio in Germany!
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