Tape Servicing
When I started in Current Ops in 1975, Tape Servicing was still next door to Current Ops, but it moved very soon afterwards to be next door to VT Despatch in the Basement Spur (always the basement!!), by the News Lifts. There were 4 Quad machines then. I spent many days in there watching keeping the 4 machines spinning. I remember reading The Hobbit and the complete Lord of the Rings while watching 8 spools spinning round. It stayed there for many years.
It later moved again to be on the end of what was then known as “The Spur Library”. Later again, it moved to a side corridor, somewhere off the main circle in the Basement and grew as it handled thousands of Beta SP (for News), D3s and Digibeta for Post Production. Ron Jas took charge of it in its last place, before he moved to selling off redundant equipment and then Brian Harris took over that and the Stock Shop.
In Gary's photo they are 1 inch machines and the 2 tall grey cabinets at the back are the tape guillotines for chopping the tape off the spools in one go. The one with the grilles is the 2“ one and the other one is the 1”. There was later a huge conveyor belt bulk eraser, that was used to erase tapes 1”, D3, Digibetas, before reuse or disposing of them
New but substandard tapes due to the dropout rate were returned to the manufacturers for replacement. Seymour Powell was head of the tape purchasing - a retirement corner.
When I joined (1962), Emitape seemed to be pretty good. Within a year it was absolute rubbish, just one long head clog from end to end - so bad and irretrievable was it that EMI gave up the tape manufacturing business, and Scotch was king. After a few years that went off and Memorex was the tape to which all brands aspired. They had a pretty good run until the dreaded white powder and thereafter Fuji reigned supreme. We didn't see much of Sony quad tape, but they were around in the 1inch and cassette era to great effect.
Ampex produced tape as well, but, it tended to be a bit abrasive, some would say it had a better potential in a belt sander than as a recording medium!
To give an idea of the effects of dropout and scratching, click the camera icon to see a short mute extract from "Presto Space" illustrating these faults.First shown is dropout, exhibiting itself in this instant as short random flashes, black or white. Scratching is a much more regular defect as can be seen in the second half. The item runs for one minute and fifteen seconds.
- It was polished. This was achieved by using a dedicated polishing head using 8 brass tips instead of the normal 4 video heads. The noise was phenomenal - nowadays Health & Safety would have us all wearing ear defenders! Incidentally, this polishing phase was conducted at normal play speed, so that a 90 minute tape took 90 minutes to polish.
- The next stage was to record black level and tone for the duration of the tape.
- This was then reviewed by the engineer who carefully monitored the video for signs of dropout (white flashes where the oxide surface was damaged) or scratching which manifested itself as regular white dotted lines coming in from the edge of the screen. He would also listen to the 1Khz tone for the duration of the tape to check for any level inconsistences or edge damage. If, in his opinion, the tape didn't have too many defects, it was passed for use.
However, John Nash was developing the first device for automatically assessing dropout on tapes, NEDE, or Nash Electronic Dropout Evaluator (or some such acronym!).
At the time I lived close to Kingswood Warren and I was 'volunteered' by Doug Parsons to spend a few weeks there using one of their two Ampex VR1000D nu-vista headed machines to help achieve the servicing targets. It was a salutory experience for a young engineer who even then wanted to be at the sharp end. The formalities of research department were a million miles from the easy going basement at TVC. One was expected to attend formal tea breaks, refrain from joking or laughing and call each other by surname. I would stare out of the window into the woodwork workshop and seriously consider that I had taken the wrong turning in life....woodwork was and still is one of my greatest pleasures.
Luckily I stuck with it, refrained from upsetting my elders ....not a skill I became renowned for.... and returned to TVC even keener to develop my new found skill editing with a razor blade and making work for those who would then have to service the quickly released programme tape for re-use. I doubt that many of those unfortunate reels that suffered at my hands were fit for re-issue except by those who had nodded off during the servicing boredom!
I don't know what vintage (A, B or C) the FR video tape machine was, but VT23 and VT24 were VR1000s (later known as A.) and 405 lines only if I recall. I know that on VT30 once, someone left a razor blade edge upwards in the Spooling Knob well, and thrusting my thumb into it in the dark, you can imagine the rest. I remember Ron Bowman giving editing practice sessions on VT30 as well.
Around 1967, VT23 and VT24 were removed to a room on the ground floor by Smith's Yard, and I remember a tape servicing session with Jack Cogswell, who didn't seemed to have a passion for it.
When Charles Paton came, in 1968, the two VR1000s were removed to specially prepared accommodation opposite Tape Despatch at TC. This had a sticky floor mat to remove dirt from shoes, and a positive air pressure with airlock type double door to keep the dust out. These two machines were joined by an ex-News VR1000C from AP. Recording Black Level and Tone and checking the replay was a bore, but later Designs Department introduced a Droput Detector to help us out. It was a chart recorder which was fed with the replayed Tone and RF from the VT Switcher Unit. The detector would integrate the dropout holes in the RF with a selected time constant, so the magnitude of the droput disturbance would be dependent on the duration of the dropout. For 625 lines, the weighting would give a higher reading, than for the same duration on 405 lines.
The two VR1000's machines could be run at a nominal 30 inches per sec.(presumably dividing the head drum PEC signal by two, instead of four). At the higher speed, less tape was scanned, and hence checked by the video head, but also the VT capstan servo was more unstable on replay. Coming back from a tea break, one would find that the chart recorder showed a large amount of dropout in places, which appeared to have been caused by the VT offtracking.
If my memory serves me, in 1972 I had to install three TR22s in place of the VR1000s. I suspect that they were from ex VT13 to VT16 stock. Don's machine movement log should help here. I had to put in Central Air for the RCA headwheels. One VR1000 went to Bristol, to a museum. One VR1000 was broken up, with most bits going to a scrap dealer, although the transport deck was given to a certain Mr. Ed Wooden. I don't know the fate of ex-AP VR1000C. See Don's log?
The VR1000 days did enable devices to be applied for longitudinal stripping of the tape for cheap audio use.
I never experienced tape servicing with the TR22s, as I moved onto maintenance at the end of the sixties. Recortecs were all in the future
This was done by fast winding the tape and listening for the splices as they passed the guide - they made a, sort of, ticking sound. Depending on the tape length, if there was a heavily edited section, that could be cut out and the tape reduced from, say, a 90 minute to a 60 minute.
The other option was to classify it as "Satis for Sport", where it might be decimated during a heavy Grandstand or Match of the Day edit.
There are many tales of Tape Servicing.........