Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   International Vintage Televisions (http://www.videokarma.org/forumdisplay.php?f=187)
-   -   Low band TV in Britain. (http://www.videokarma.org/showthread.php?t=268104)

Colly0410 11-24-2016 04:18 PM

Low band TV in Britain.
 
Low band (band 1) in Britain was 5 channels numbered 1 to 5 & carried BBC1 using the 405 lines system. (6 was in high band) There were 5 high power transmitters, one on each channel. Channel 1 was used by Alexandra Palace then Crystal Palace (from 1957) for the London area, channel 2 from Holme Moss for northern England, channel 3 from Kirk-O-Shotts for central Scotland, channel 4 from Sutton Coldfield for English midlands & channel 5 from Wevoe for South Wales & West of England, all with vertical polarisation, (Rods vertical) these covered most of the population by the early 50's. They then started to reuse channels for medium power stations: channel 1 was used by Divis for Norther Ireland, channel 2 from North Hessery Tor for South Devon & east Cornwall, channel 3 from Isle of Wight for Southern England, Channel 4 from Meldrum for North east Scotland & channel 5 from Pontop pike for North east England. The medium power stations used a mix of both horizontal & vertical polarisation to try & reduce co-channel interference. Then from the mid 50's the low band exploded with dozens of medium & low power stations up till the mid/late 60's, all carrying BBC1. High band was used by ITV starting in 1956 & in the mid 60's for a few BBC1 transmitters...

compucat 12-05-2016 08:19 PM

Quote:

Originally Posted by Colly0410 (Post 3173782)
Low band (band 1) in Britain was 5 channels numbered 1 to 5 & carried BBC1 using the 405 lines system. (6 was in high band) There were 5 high power transmitters, one on each channel. Channel 1 was used by Alexandra Palace then Crystal Palace (from 1957) for the London area, channel 2 from Holme Moss for northern England, channel 3 from Kirk-O-Shotts for central Scotland, channel 4 from Sutton Coldfield for English midlands & channel 5 from Wevoe for South Wales & West of England, all with vertical polarisation, (Rods vertical) these covered most of the population by the early 50's. They then started to reuse channels for medium power stations: channel 1 was used by Divis for Norther Ireland, channel 2 from North Hessery Tor for South Devon & east Cornwall, channel 3 from Isle of Wight for Southern England, Channel 4 from Meldrum for North east Scotland & channel 5 from Pontop pike for North east England. The medium power stations used a mix of both horizontal & vertical polarisation to try & reduce co-channel interference. Then from the mid 50's the low band exploded with dozens of medium & low power stations up till the mid/late 60's, all carrying BBC1. High band was used by ITV starting in 1956 & in the mid 60's for a few BBC1 transmitters...

Fascinating. I lived in Scotland just outside Glasgow in the early Seventies and there were only three channels, BBC1, BBC2, and STV. I don't remember what dial positions they were on though. I do remeber when our 13 inch colour tv broke down the repairman said he had to take it to the shop because it was "one of those new transistorised sets" and he could not fix it in the house.

DavGoodlin 12-07-2016 09:08 AM

Thanks for the lesson on how BBC covered the UK, Colly. Those transmitter locations sound so challenging to receive , considering the terrain is so similar to the northeastern US. A British website "antennahacks" is very interesting and details their adventures. They discuss trees and foliage, especially evergreens, and how they affect UHF reception.

Having visited there a few times since the mid-70s, I saw mostly UHF yagi antennas.
I recall a hotel room in London with a Philips monochrome set having a loop antenna and pushbuttons set like a car radio. They were variable and numbered and I seem to recall channel 21 and 27 as BBC 1&2.
I saw the occasional VHF antenna, vertical polarised and just figured that was for FM broadcast. The X antennas I was told were omni-directional FM, probably a radio 4 listener who wanted their classical music crystal clear.

Low band VHF DTV is alive and expanding in the Philadelphia-South Jersey area. Channels 2 and 4 have been built. A channel 5 now in Middletown Delaware.

WPVI 6 (85 mhz center band) has upped their power a few times since 2009 because most people buy a set-top UHF antenna which pulls in all the other transmitters and usually the one and only hi-band channel 12. I mean, who wants a 64 inch dipole hanging off their set:sigh:

About 12 years ago, some analog stations were simulcasting in ATSC on a different channel, UHF mostly. I began experimenting with DT reception and collecting classic UHF designs to test. A long-time TV repair acquaintance predicted the channel assignments would change but the lo/hi VHF and UHF bands would remain. He was telling everyone to keep or upgrade their broadband antennas even suggesting the big combination antenna monsters like the Channel Master CM3671 and Winegard 8200, both about 4 meteres from front to back.

ppppenguin 12-07-2016 11:14 AM

Until analogue shutdown in 2012 the main London TX used these channels:

ITV: 23 (from 1969)
BBC1: 26 (from 1969)
Channel 4: 30 (from 1982)
BBC2: (from 1964) 33
Channel 5 (from 1997) 37

All horizontal polarisation.

BBC1 405 line was on channel 1 (45MHz vision, 41.5MHz sound) until 405 shutdown in 1985
ITV 405 line was on channel 9 until 405 shutdown in 1985
Both vertical polarisation.

There's a surprisingly large number of Band 1 and Band 3 aerials still surviving on people's chimneys. A lot of the Band 1 aerials were X shaped.

VHF FM radio was trasnmitted from 1954 in Band II. Originally with horizontal polariastion, now with mixed polarisation which is better for portable and mobile reception. You don't see many Band II outdoor aerials as most people don't bother. The horrible little "halo" aerials have less gain than a dipole but work well in many areas. I have one on my chimney.

DAB digital radio is broadcast in Band III, vertical polarisation. An old ITV Band III aerial often works quite well even though the frequency is a a little low. Again most people just use the set's own telescopic aerial.

Electronic M 12-07-2016 11:45 AM

Say, after 625 color came on line in Brittan did anyone make/sell monochrome sets that could tune and display 625 in monochrome?

ppppenguin 12-08-2016 01:44 AM

There were plenty of 625 only monochrome sets after the introduction of colour. A colour set in 1967 cost about GBP300, about GBP5000 or $14000 in today's values allowing for inflation and the exchange rate of the time. This would have been an expensive luxury. A monochrome set would have been about 5 times cheaper.

In the UK the BBC is funded via a licence fee levied on all TV users. You may or may not agree with this system but that's what we do here. There was an additional licence fee for colour. Incredibly there is is still a different licence fee for monochrome only with a few thousand still around: http://www.telegraph.co.uk/news/news...white-TVs.html
While I strongly suspect that most (not all) of these people are breaking the law by using a colour set I also suspect it's a political decision not to pursue them. At some point the numbers will drop to almost zero and the monochrome licence will be abolished.

For comparing prices over time I use this excellent website:
https://www.measuringworth.com/ukcompare/

Common monochrome 625 only sets in the UK included many designs based on the Thorn 1500 chassis and on the Rank Bush-Murphy A774 chassis. Example of a 1500 set on this page: http://www.golden-agetv.co.uk/equipm...?ProducerID=12

Colly0410 12-08-2016 12:30 PM

Unfortunately nearly all the VHF TV antennas (aerials) have gone from the British rooftops. (Well in the Nottingham area they have) When my Canadian cousin came to stay with us in Nottingham in the mid 1960's he was fascinated with all the vertical H & X shaped antennas on just about every rooftop. I asked how they went on in Ottawa? He said "everyone had a rabbit ears antenna on top of the TV." Some people had a cable system called Rediffusion but it only got the same 2 TV channels that you got off the Antenna TV. Only posh people with plenty of money had UHF TV's on 625 lines. Until Nov 1969 the only program on UHF was BBC2, when BBC1 & ITV fired up on UHF in colour then UHF antennas appeared on the the rooftops. Sometimes the VHF antenna was taken down, but often they were just left there to fall to bits over the years. In my own case I used the VHF antenna for FM radio, it was still there when I joined the army in 1977 & went to Germany, when I came back in 1981 it had gone, "blown down in a gale" my parents said. Hardly anyone used VHF TV after the early 70's, they'd all gone over to UHF 625 lines in black & white or colour...

Colly0410 12-09-2016 12:08 PM

For some reason unknown to me all the high power & some medium & low power VHF TV transmitters in Britain used vertical polarisation, (rods vertical) I don't think any other country except New Zealand did this. When I've been to USA, Mainland Europe & Russia all the VHF antennas were horizontal polarisation. At UHF all the Brit high power transmitters use horizontal polarisation & most low power are vertical, this is to try & cut down on co-channel interference...

Adlershof 06-03-2017 03:42 PM

But in the right locations in continental Europe you can still see (now as useless remains of course) vertical VHF antennas, because certain transmitters used this polarization to ease channel reuse. In Germany this was the case in band 1 with the Ochsenkopf transmitter (ch. 4) and on a number of cases in band 3, such as Visselhövede on ch. 7, Wiederau on ch. 9, Dresden and Heide on ch. 10. Also some UHF high power transmitters used vertical polarization, at least Marlow (ch. 24 plus later added ch. 43).

In other countries this was less common, but still it happened. One example, at least if literature can be trusted, was the old band 2 (OIRT ch. 4) transmitter in Vilnius.

Colly0410 10-06-2017 11:36 AM

Up until 1955/56 TV's were only fitted with a low band tuner, they were called "BBC only" sets. When ITV started on high band in 1956 all new TV's could receive both low & high band. You could get ITV converters to change a high band channel to a low band one, sometimes you got BBC breakthrough though..

Electronic M 10-06-2017 12:25 PM

Quote:

Originally Posted by Colly0410 (Post 3190316)
Up until 1955/56 TV's were only fitted with a low band tuner, they were called "BBC only" sets. When ITV started on high band in 1956 all new TV's could receive both low & high band. You could get ITV converters to change a high band channel to a low band one, sometimes you got BBC breakthrough though..

It would be funny if that ever happened in time to hear John Cleese say "...and now for something completely different." in a Monty Python episode. :D

Colly0410 10-07-2017 06:08 AM

England has a history of older TV's not being able to receive new stations, you had the BBC only sets not able to receive ITV in the late 50''s/early 60's, (no high band tuner) then 405 lines VHF only sets not being able to receive BBC2 on 625 lines UHF in the late 60's/early 70's. Then more recently the digital changeover, but you could & still can buy cheap digital converters, I've got 4 of them, 2 with RF outputs for my really old TV's (1971 Elizabethan & 1985 NEI) that don't have SCART or HDMI inputs...

Sandy G 10-08-2017 08:06 AM

Somewhere in the back of my feeble little mind, I THINK I remember reading that a lot of the early color experimentation in Blighty was done on 405...

Colly0410 10-08-2017 09:27 AM

Quote:

Originally Posted by Sandy G (Post 3190442)
Somewhere in the back of my feeble little mind, I THINK I remember reading that a lot of the early color experimentation in Blighty was done on 405...

Yes I believe that is true, I've read that NTSC looked very good on 405 lines. On 625 lines the BBC tested NTSC, PAL & SECAM, they eventually chose PAL for hue stability. Read that some ITV companies wanted SECAM, & most set makers wanted NTSC...

ppppenguin 10-09-2017 01:03 AM

SECAM was a nightmare in the studio. You can't fade or mix it without severe compromises. I once worked for Michael Cox Electronics who made genuine SECAM vision mixers. Hideous things, with no possibility for them to be any better. It's no surprise that France was in the vanguard of component (YCbCr) colour studio techniques. In some SECAM countries they took a pragmatic approach and ran the studios in PAL, transcoding to SECAM for transmission.


All times are GMT -5. The time now is 12:36 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.