How were tapes wiped?

[ianphillips]

So, it's common knowledge that BBC Engineering wiped their master tapes, but is it known what process they used to do so? Namely, did they erase them first and then record over them or just overwrite them without first erasing, or did they use both methods?

[John Wall]

The simplest way is with a magnet.

[Patrick Hugunin]

I worked at various TV stations through the 80's till now. We had a bulk eraser machine which we ran our tapes through. Sometimes we just recorded over the original tape without wiping it first. We always had to check the recording afterwards to make sure the old recording did not bleed into the new ones.

[ianphillips]

Do we know how the Doctor Who tapes were wiped and what other programs were put on them afterwards, because I know that it's sometimes possible with professional recovery equipment to retrieve low quality versions of the ends of tapes which have been directly overwritten as long as the new program written to it is shorter than the original.

[John Wall]

Dr Who was 25 minutes - most BBC programmes were longer.

[Dave Wood]

Dec 22, 2016 19:15:43 GMT ianphillips said:

Do we know how the Doctor Who tapes were wiped and what other programs were put on them afterwards, because I know that it's sometimes possible with professional recovery equipment to retrieve low quality versions of the ends of tapes which have been directly overwritten as long as the new program written to it is shorter than the original.

From memory I'm pretty sure this was raised and explored a few years ago, but sadly very few 1960's tapes exist, even if it were feasible and affordable. I seem to recall that the only tape know to survive that was previously used for a 1960's Who recording was wiped and reused to record an edition of Blue Peter. The original Who episode that was once on that tape was Enemy of the World 3, rather than anything missing from the BBC archives.

[Gary Critcher]

When I worked in VT Current Operations at Television Centre there was 2 ways we wiped tapes. One was a 'de gausser' machine where you literally laid the reel onto a short conveyor belt which then passed the tape through two strong electro magnets which wiped the tape. We were advised not to take put our credit cards too near that machine. The second way was by running the tapes through a 'Recortec' machine, which evaluated the tape on the first pass, gave you a print out of the defects on the tape and then rewound it. Here's a link to pic of me doing just that back in 1985: www.vtoldboys.com/tservice01.htm

[RWels]

Dec 30, 2016 21:22:11 GMT Gary Critcher said:

When I worked in VT Current Operations at Television Centre there was 2 ways we wiped tapes. One was a 'de gausser' machine where you literally laid the reel onto a short conveyor belt which then passed the tape through two strong electro magnets which wiped the tape. We were advised not to take put our credit cards too near that machine. The second way was by running the tapes through a 'Recortec' machine, which evaluated the tape on the first pass, gave you a print out of the defects on the tape and then rewound it. Here's a link to pic of me doing just that back in 1985: www.vtoldboys.com/tservice01.htm

But you are not Gary Critcher?

[Gary Critcher]

Aren't I? I was the last time I looked.

[Simon B Kelly]

Dec 30, 2016 23:01:55 GMT Gary Critcher said:

Aren't I? I was the last time I looked.

You should change your display name to your real name then, as per forum rules. Click on Profile -> Edit Profile -> Personal to do this. (This doesn't affect your username)

[Gary Critcher]

'You should change your display name to your real name then, as per forum rules. Click on Profile -> Edit Profile -> Personal to do this'
done !

[RWels]

Dec 31, 2016 0:18:34 GMT Gary Critcher said:

'You should change your display name to your real name then, as per forum rules. Click on Profile -> Edit Profile -> Personal to do this'
done !

Ah well, you see why I was confused. Also, I am not sure, but didn't you already use to have an account here years and years ago?

[brianfretwell]

The bulk eraser I used in a computer centre I worked it was capable of erasing 2" video tapes and even had printed on it that there was an adapter to make this easier for large reels. It was a platform with rollers that attached at the front to prevent wrist injuries when inserting the tape into the slot in the front.

The main way of erasing suggested was to insert the tape slowly allow the sprung plate inside to return the tape, rotate it 90 degrees, flip and repeat the procedure, to ensure complete erasure.

[Pete Morris]

They were wiped like this:

www.youtube.com/watch?v=TTUhGlH8OS4