Our Territories

Channel Islands
England
Ireland
Isle of Man
Scotland
Wales

Our Categories

Home
Locations
Surnames
Articles
Library
Lookups

In 1951 Wireless World published a series of articles on building a 12” B/W television of professional standards. The series were exceptionally good they gave details of jigs which could be made for winding deflector coils the whole series were designed to the highest standards and the finished coils turned out to be a most efficient scan coil unit.

Following the instructions slowly ensured a first class result, Having the instructions and data being given out in small doses held me back from my usual rush which in turn paid by giving me first class results. Chassis dimensions and details were good and I quite quickly had the various chassis complete and tested. Many Ex-RAF EF50’ valves were used these giving me excellent performance. On the Extra High Voltage side unfortunately a very high voltage transform was used which had huge capacitor smoothing all having there “dangers” and problems with insulation. During my early trials while operating on the 12”dia round screen face we noticed that the rectangular picture .we noticed the image began to tilt over on an angle To correct what I thought was a scanning fault I was bussed myself adjusting the frame and line hold controls within the scanning unit not realising it was the tube itself which had begun to roll off the table! It did and I was just in time to catch the neck before to fell to the floor. I had overlooked the danger of the EHT lead and was soon reminded of it when received a sharp shock and the pain of 5000 volts discharging across my hand this caused my grip tightened even though I had not planned for it. Fortunately the built in overload came in and the EHT power circuit was broken cutting off the supply perhaps just in time!

With the year I have tried various types of commercial cine cameras in the early period I used a clockwork Pathe 9.5 mm camera a really neat unit using Black and White film only quality was only fair and the system was superseded by the 16mm film which was available in colour and which was sent away for developing and cutting and would be returned as 8 mm spliced and ready to be projected.

I soon realised that this way of filming worked out very expensive and using photographic film brought in delays awaiting processing. Also the time the films took since taken and my poor memory ! I had forgot what settings had been used for the original shots. And could not correct the faults. What was required was something much quicker.

In 1956 Television programmes were sometimes being recorded on 2” and 4” wide magnetic tapes which would replay such programmes at a later date. The unions at the time saw to it that such systems were not used for live programmes too many were involved in Film production and it’s processing. I made enquiries about the machines they used and found smaller portable units were available but at a huge price more than one would pay for a top of the range motor car. But I did come across details of the enthusiasts DIY video recorder using sound quarter inch recording tape and special induction recording heads. Full details were never made available but I was able to get enough details to have a go making my own unit.

Quarter inch tape was available on 7” Spools and by using my old disused sound recording heads modified to induce magnetic signals through the tape onto a special Recording head. This head was made using a special “fine gapped induction head” which actually contacted the magnetic surface of the tape yet had no electrical connection to the circuit. The magnetic tape was fed through at high speed by a spindle type drive roller. I had plenty of the drive pulleys acquired from old sound recording

Previous | Index | Next