Co-ax V 300 ohm flat twin.

[ppppenguin]

I know the UHF channel planning was co-ordinated with our neighbours in continental Europe. If you hunt through BBC Research reports you may find details of this and of earlier Band I/III co-operation.
https://www.bbc.co.uk/rd/search?Type=Publications

[Terry]

The transmitter was at Liege in
Belgium on Ch E3 with horizontal polarisation.

Interesting because Tacolneston is about 175 miles from Rowridge, which aimed its power northwards to cover southern England whereas Liège is around 230 miles away.  Liège is the capital of Wallonia* - southern Belgium - and is way over in the east so its  power would mainly be directed roughly in a south westerly direction. That would place Tacolneston behind the majority of receiving aerials.

The sound carrier of channel B3 is 500kHz below the sound carrier of E2 and 250kHz above the upper sideband limit of E2, so I can't see that there would be any problems with that channel at all.  

Quite frankly, I can't see why there should have been a problem.

* Liège is virtually on the invisible frontier that separates French speaking Wallonia and Dutch# speaking Flanders. The 'frontier' runs east - west across the country.

# Flemish is a number of local dialects of Dutch. All Radio and Television broadcasting in Flanders is in Dutch.

[Mr Hoover]

The BBC report of the Tacolneston
service area is below,mentions
Liege transmitter.
Suspect they were being on the
cautious side.
https://www.bbc.co.uk/rd/publications/rdreport_1959_06

[Terry]

In the table at the end I note that the signal levels at Beccles and Bungay are quite respectable when compared with many of the other readings.

When I went to that area in 1959, I was fascinated by the three element yagis on all the houses - I was used to single dipoles for Crystal Palace with the occasional H or Z - but mostly because of the way the ends of the elements drooped down, making them look like some form of giant insect swooping over the roofs!

Some of those other areas must have needed quite impressive arrays, based on that table.

One other memory of that visit - adverts on all of the buses saying that Anglia Television was starting on 27th October 1959!

[Synchrodyne]

European VHF frequency planning was done at the ITU 1952 Stockholm meeting (ST52).  However, there were many subsequent changes, as some participating countries submitted only provisional plans that were quite different to what was actually adopted post-ST52.  A small part of that comes out in this current VRAT thread:  https://www.radios-tv.co.uk/community/bl...post-97389.  The UK was a participant at this meeting.

The ITU 1961 Stockholm meeting (ST61) was mostly about European UHF frequency planning, but at the same time the VHF assignments were updated.

According to the attached WW 1953 August article, Tacolneston was originally planned as using channel 6.  But the BBC was denied access to Band III at the time, and had to rework its national coverage plan to use only the Band I channels.  The net result was that Band I was oversubscribed, and Band III was underutilized.  The BBC required noticeably more Band I transmitters (and eventually a small number in Band III) to achieve national coverage than did the ITA using Band III alone.  Given that Band I signals generally travel further than those in Band III, one might expect it to have been the  other way around.  But with the overstuffing, the Band I distance capability was a liability.  Second-level transmitters needed to have carefully controlled erps and directionalities so as not to interfere with the main transmitters, and that resulted in coverage gaps as compared with what might have been possible had clear or reasonably clear channels been available.  So infill transmitters were required and so it went on.

       

Three-element Yagis were I think the most common TV aerials around Auckland, NZ in the 1960s.  Small arrays were much less common, less seen than larger types, such as 4-element.  Channel NZ2 was 54-61 MHz (the same as E3), and not too much different to B3 (53-58 MHz).  But our Yagis all had folded dipoles, which made them more rigid mechanically, although the reflectors and directors sometimes suffered from end-droop.  The latter was much more visible in Wellington, where channel NZ1 (44-51 MHz) was used, requiring noticeably longer aerial elements; wind damage was also a major problem.


Cheers,

Steve

[Synchrodyne]

The attached article from Electronics World 1970 January gives a picture of the American situation at the time.  Clearly, by then 75-ohm coaxial was very much an established alternative to 300-ohm twin.


  EW 197001 TV & FM Leads-In.pdf (Size: 2.12 MB / Downloads: 3)

This advertisement from 1966 I think represents an early incursion of 75-ohm coaxial into what was then still a 300-ohm twin domain.

   

But screened 300-ohm twin was also a contender, one that in the event was pushed aside by 75-ohm coaxial.

   


Cheers,

Steve