Instruction folder for kit television,
plus an example of the kit.
Cover of 1st Edition of Practical
Television (April 1950)
In the late 1940's Wireless World published a design for television reciever for home construction. At the same time a few companies were marketing television kits. With such interest in television Practical Wireless added a seperate television section to it's magazine. With the opening of the Birmingham transmitter in December of the previous year it was deemed that there was enough demand to seperate the television section from the magazine, as a result of which "Practical Television" was launched in April. The magazine continued until quite recently.
In the first half of the year Link Sound and Vision Ltd, a company formed jointly by Pye and Murphy, install the first British relay link to cover an area (as opposed to blocks of flats). The system was installed in Gloucester, picking up transmissions from the new Sutton Coldfield transmitter. Subscribers to the service were charged 7s 6d per week, the charge including the license fee.
International TV Link
|Hotel de Ville, Calais||Relay route to London||Televised scene.|
On August 27th (date to be confirmed), which was the centenary of the first
cross-channel telegraph, the B.B.C. made the first cross-channel television
link. Indeed, this was the worlds first live international television link.
The link ran for 91 miles from outside the Hotel de Ville in Calais, France,
across to Dover and from there onto Broadcasting house via several repeater
stations. The program was also transmitted on to Sutton Coldfield in Birmingham.
The B.B.C. also made a short film on how the event was televised, titled "How Television Crossed the Channel.
The industry saw this achievement as a great success and in July the Radio Industry Council wrote to the Postmaster General requesting the establishment of a permanent link "without delay".
Whilst London's Alexandra Palace had been the only transmitter in operation there had been little reason for manufacturers to iintroduce a TV set that was in any way tuneable for different stations.
The first provincial transmitter (Birmingham) had recently come into operation with plans for a further three transmiitters well under way. Initially manufacturers continued to manufacture single-channel sets, pre-tuned to either Channel 1 (London) or Channel 4 (Birmingham). The exception was Bush, who were the first to introduce a set (the model TV22) that could be easilly tuned by the owner to any one of the 5 proposed BBC channels. Whilst this might not have meant much to any owner unless they happened to move to a different part of the country (which would have been a rare occurance) it was of great benefit to the manufacturer and service outlets who only needed to support a single varient.
January sees the anouncement by the American company Hytron Radio and Electronics Corporation of a new C.R.T., the 16-inch 16RP4, which was rectangular in shape as opposed to the round designs that had hitherto been used exclusively. However it was not the first such C.R.T., Germany having introduced a television using a rectangular C.R.T. before the war.
Towards the end of the year English Electric introduce a CRT with a spun steel conical body and glass face plate. It was claimed that the design was easier to produce as well as being lighter and more rhobust.
Change of Aspect Ratio
From April 3rd the aspect ratio of the picture transmitted by the BBC is increased from 5:4 to 4:3, the latter being the format used by 35mm and 16mm film. If existing sets were not readjusted then they would show the circle in the middle of the test card as an oval ; if adjusted to display a circle then either the picture height would need to be reduced (by ¼ inch top and bottom on a typical 9" receiver), or be adjusted to crop the left and right of the picture.
|Pye LV30 / BV30||Identical sets under conditions of fairly high external
The right-hand set has a neutral tinted perspex filter.
In June, Pye introduce the first British dark screen TV's, the models LV30 and LV30C based on an American idea. The principle idea was to reduce the effects of ambient lighting which would otherwise reduce the contrast of the picture.
In April Mullard announce theintroduction of the ECL80, a triode-pentode, and the EF80 r.f. pentode. The EF80 gave similar performance as the EF42 and EF91 but at a reduced H.T. voltage of only 170V, an important improvement for sets using an AC/DC chassis.
Amongst their "world range" of valves released during the year, Mullard introduce the PL81. This miniature glass valve ousted the octal PL38 as the choice for line output stages and had characteristics that also made it suitable for use in single-valve timebase circuits.
Early in the year the experimental Dutch transmitter installed by Philips the previous year was changed from it's original 567-line system to 625-lines. At the time it was estimated that some 400 amateyr receivers had been constructed.
In America two companies (Zenith in Connecticut and Skiatron in New York) begin experimental transmissions of scrambled-signal pay-TV.
France had 15,000 television sets in use in the Paris area. Television had yet to reach the rest of the country, however in the the first half of the year (possibly May?) a new 300-watt transmitter at Lille made some experimental 819-line transmissions. Of the 225 French radio manufacturers present at the Foire de Paris in May, some 30 manufacturers demonstrated 819-line receivers.
At the start of October the Netherlands begin their first regular transmissions. They are transmitted from a converted chapel in Amsterdam.
In September Mexico begins a commercial television service. It is the first television service in Latin America.
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29th October 2006