Graeme Wall wrote in message
:

In message
"Ronnie Clark" wrote:

It was quite some time before more advanced editing techniques made
it possible to record a whole serial in one go, however I vaguely
recall that it started in the middle of the third series.

Not quite sure what you mean by this, presumably you are referring to
the advent of electronic editing.

What was it that precluded electronic editing by dubbing from one tape to
another, as they did until a few years ago? Was it simply that copying from
one tape to another in the early days brought the quality below acceptible
broadcast standards?

On Mon, 6 Feb 2006 22:58:58 -0000, "Martin Underwood" a@b wrote:

Graeme Wall wrote in message
:

In message
"Ronnie Clark" wrote:

It was quite some time before more advanced editing techniques made
it possible to record a whole serial in one go, however I vaguely
recall that it started in the middle of the third series.

Not quite sure what you mean by this, presumably you are referring to
the advent of electronic editing.

What was it that precluded electronic editing by dubbing from one tape to
another, as they did until a few years ago? Was it simply that copying from
one tape to another in the early days brought the quality below acceptible
broadcast standards?


Not exactly.

It was that at the join the to get an imperceptible edit the sync
pulses had to be continuous, and take into account that Broadcast TV
used interlaced scanning with even and odd frames so a complete even
frame should be joined onto a complete odd frame, (& vica -versa) or a
disturbance would be apparent on viewer's sets, (18 million sets would
do a frame roll (at least) &/or display a noise band/ lose line hold.

The VTR's "control track" was also written onto the tape along with
the sound and video, this kept the heads running down the middle of
the tracks written on the tape, and a gap in this might mean the
playback VTR's servos went out of lock and the heads lost their
tracking taking some time, maybe a few seconds, to lock back in.

Also as the splice went through it 's possible that oxide/ adhesive
/clag would be ripped of the tape and cause a head clog. Video tape
was expensive but I doubt if a tape with a physical edit in it would
be re-used to record a new programme because of this risk.

I can't remember seeing physical videotape edits going through on the
telly, though "Non-Sync Cuts" were fairly common into the early '70s,
where millions of home TV's would Colour Kill, and Frame Roll,
especially cutting to/from inserts from Europe or Ireland.

Altogether Nasty.

When PAL colour first came along, that used vertical axis switching in
the colour signal, as well as frame interlacing, so it turned out that
there was a rotating sequence of 8 distinctive frame types, and edits
had to be made such as to preserve that sequence. that can only be
done electronically between two sources which can be synced up
together and IGWS for that matter are also in "colour sync" as well
as.

The signals had to be timed up to be accurate within the odd
microsecond or less, otherwise their would be a bigger and better, and
now *coloured* disturbance. It needed digital electronics to do that.
It can't be done by looking through a microscope, or by varying the
volts on an electric motor.

Perversely the French SECAM system was more rugged in this respect and
editing colour videotapes was simpler for them, they could just go
instantaeneously from play to record if they were B&W synchronous.

However, since their colour information was carried on an FM
subcarrier signals from 2 sources couldn't be simply added together,
(Effect smilar to 2 radio stations on top of one another) so their
vision mixers were more complicated and less satisfactory than ours,
having to decode the signal to RGB and re-encode at all positions in
between 0% and 100% on the fader.

That, at least, is some consolation.

DG

In message
"Martin Underwood" a@b wrote:

Graeme Wall wrote in message
:

In message
"Ronnie Clark" wrote:

It was quite some time before more advanced editing techniques made
it possible to record a whole serial in one go, however I vaguely
recall that it started in the middle of the third series.

Not quite sure what you mean by this, presumably you are referring to
the advent of electronic editing.

What was it that precluded electronic editing by dubbing from one tape to
another, as they did until a few years ago? Was it simply that copying from
one tape to another in the early days brought the quality below acceptible
broadcast standards?



The 10 second run-up of a tape machine (or telecine) to achieve sync was a
problem until electronics were devised to enable the machines to go from play
to record on the fly at a predetermined point. Eventually Ampex devised a
quad machine that would do instant starts, first used on the Andre Previn
concerts.

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

In message , Graeme Wall
writes
The 10 second run-up of a tape machine (or telecine) to achieve sync was a
problem until electronics were devised to enable the machines to go from play
to record on the fly at a predetermined point. Eventually Ampex devised a
quad machine that would do instant starts, first used on the Andre Previn
concerts.

I was at a loose end in South Kensington for a couple of hours last week
and went along to the Science Museum to pay my respects to "Rocket".
While mooching around I actually stumbled on one of these early (very
early as it turned out) Ampex Machines. Apparently
Associated-Rediffusion imported the first one from the US to the UK.
--
Ian Jelf, MITG
Birmingham, UK

Registered Blue Badge Tourist Guide for London and the Heart of England
http://www.bluebadge.demon.co.uk

On Tue, 7 Feb 2006, Ian Jelf wrote:

I was at a loose end in South Kensington for a couple of hours last
week and went along to the Science Museum to pay my respects to
"Rocket". While mooching around I actually stumbled on one of these
early (very early as it turned out) Ampex Machines.

If anyone else is old enough to grok the word-play - I once
saw a cartoon of the VERA equipment at the BBC, with the caption
"Someone isn't using Ampex".

In message c.uk
"Alan J. Flavell" wrote:

On Tue, 7 Feb 2006, Ian Jelf wrote:

I was at a loose end in South Kensington for a couple of hours last
week and went along to the Science Museum to pay my respects to
"Rocket". While mooching around I actually stumbled on one of these
early (very early as it turned out) Ampex Machines.

If anyone else is old enough to grok the word-play - I once
saw a cartoon of the VERA equipment at the BBC, with the caption
"Someone isn't using Ampex".

Hmmm!

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

Graeme Wall wrote:

The 10 second run-up of a tape machine (or telecine) to achieve sync was a
problem until electronics were devised to enable the machines to go from play
to record on the fly at a predetermined point. Eventually Ampex devised a
quad machine that would do instant starts, first used on the Andre Previn
concerts.

Was that the AVR1?

In message .com
"Stephen Furley" wrote:


Graeme Wall wrote:

The 10 second run-up of a tape machine (or telecine) to achieve sync was
a problem until electronics were devised to enable the machines to go
from play to record on the fly at a predetermined point. Eventually
Ampex devised a quad machine that would do instant starts, first used on
the Andre Previn concerts.

Was that the AVR1?


Possibly, sounds vaguely familiar. To be honest I don't really know, I was
on the gallery end of the chain and it was just VT69 (or whatever) as far as
I was concerned.

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

"Graeme Wall" wrote in message
...
In message .com
"Stephen Furley" wrote:


Graeme Wall wrote:

The 10 second run-up of a tape machine (or telecine) to achieve sync
was
a problem until electronics were devised to enable the machines to go
from play to record on the fly at a predetermined point. Eventually
Ampex devised a quad machine that would do instant starts, first used
on
the Andre Previn concerts.

Was that the AVR1?


Possibly, sounds vaguely familiar. To be honest I don't really know, I
was
on the gallery end of the chain and it was just VT69 (or whatever) as far
as
I was concerned.

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html
And , of course, 'it was all right leaving you', Graeme....
Brian

In message
"BH Williams" wrote:


"Graeme Wall" wrote in message
[snip]

Possibly, sounds vaguely familiar. To be honest I don't really know, I
was on the gallery end of the chain and it was just VT69 (or whatever) as
far as I was concerned.

And , of course, 'it was all right leaving you', Graeme.... Brian


Of course! I used to know that phrase in Russian, relic of an early
satellite tx.

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html