Television Demonstration during World War II

Peter wrote:

It is difficult to understand what any potential broadcast would do for the war effort but if it was to test the equipment it may have been for another purpose? My only thought on TV during wartime was as a guidance system for a missile (powered or free-fall) but I didn't think the British were investigating that but I believe it was being looked at by the Americans and the Germans. This is all from a distant memory of either a book or a TV programme so I may be totally wrong.

One book (either Pawley or more likely one on Section VIII) says that the German (tanks?) used frequencies around those used by the early British TV transmissions during the Blizreig into France so Alexandra Palace was set up so it could be used to jam those frequencies in the event of an invasion. It would probably be put out of action by the Luftwaffe but disruption of communication in the first couple of days could be crucial.

canberra wrote:

AFAIK Alexandra Palace was the only TV transmitter prior to wwii, could the signal be picked up in Cheltenham? My mums next door neighbours in St Albans did have a set, they used to switch it on once a week during wwii to keep it warmed up so to speak.

But Im still not convinced about why the service was shut down in September 39. The official reason was so that the frequency wasnt used by the Germans for navigation, so what about radio frequencies??????

The initial television transmissions were from Selfridges' roof, then Brookmans Park.

The TV service closed for a variety of reason, main one being that it was not an essential service and was only watched by a small number of people. The BBC was heavily committed during the war with many staff being called up and took in women and boys too young for the forces. The last thing they needed was to have to divert resources to television.

Measures were taken to make it difficult for the Germans to use the Medium Wave transmitters for navigation. All the transmitters were synchronised on the same frequency and low power transmitters were placed around each high power one. I think they helped to make it difficult to use the transmission as beacons. There was a system to shutdown the main sites if there was air raid expected in the area but limited coverage was provided by the low power transmitters. A high power VHF transmitter on a high location near London would have made fantastic navigational beacon for Luftwaffe!

Try and get hold of a copy of this book, it is long out of print but there should be copies in major libraries.

BBC Engineering, 1922-72
Edward Lewis Ellman Pawley
563121270

It is an excellent book and is actually very "readable" even though there is a lot of information there.

There is a summary in there - it is in a quarterly(?) publication also called BBC Engineering.

I must flag it on ABE, just see how many copies around but I think they are very rare. Pity they can't do a facsimile copy as has happened for many other books but they are often poor quality reproductions. I have an original copy of the 1919 US Navy book on the Northern Barrage (North Sea minefield). I have seen copies on places like Amazon and wondered about them. I took it up to a meeting about a project researching WWI. One person had one of these facsimile copies but said mine was far superior even though the photographs are certainly not high quality prints .

Apparently the NIIR system was based on an unpublished by a BBC engineer.

I remember being told that a deputation from one of Eastern block countries visited one of main BBC transmitters, over lunch someone asked them why they chose SECAM. He was told it was because their distribution network and / or transmitters were such poor quality that it was the only system that could be used.