On 30/05/2021 13:22, Alexander wrote:
>
>>> requiring a decoder to be installed at every 405 transmitter side nationwide.
>> Well, they (or the Oracle office) could have switched the captions on
>> and off at will by using the subtitle/newsflash commands totally within
>> the teletext system.
>>
>> 405 line switch off was a three year gradual process, so not all the
>> sites would have required decoders all at the same time.
> This all sounds a bit fishy. :-)
>
> I thought the vast majority of transmitters ceased radiating 405
> on or around 4th January 1985, unlike the closure of 625 PAL
> which was a drawn out process over several years.
No, not at all was done it batches every three months, starting in April
1982, and ending in January 1985.
I think only a handful were left by Jan 85. The Beeb had about 100
sites, the IBA had 47, (though most of those were relays)
BBC and ITV transmitters in the same area were switched off together.
For instance, BBC Oxford, Hungerford, and Marlborough, the same day as
ITV Membury,

I doubt any captions were possible on the relays though (unless the
parent was being switched off the same time).

Take a look at some of the IBA Engineering info progs on You Tube from
the era.

Naturally the large population sites were the last to go, CP, Croydon,
Holme Moss, Emley, Winter Hill etc...
> I had a look through a couple of ITV 'teletext recoveries'
> from late 1984 (recovered from VHS tapes with special software),
> but no sign of any captions hidden in there.
Well, they were there, I seem to recall the one I saw was on TVS's
'regional' sub-pages.

In article <ihhohrF5ukmU1@mid.individual.net>, Mark Carver
<mark.carver@invalid.invalid> wrote:
> On 30/05/2021 13:22, Alexander wrote:
> >
> >>> requiring a decoder to be installed at every 405 transmitter side
> >>> nationwide.
> >> Well, they (or the Oracle office) could have switched the captions on
> >> and off at will by using the subtitle/newsflash commands totally
> >> within the teletext system.
> >>
> >> 405 line switch off was a three year gradual process, so not all the
> >> sites would have required decoders all at the same time.
> > This all sounds a bit fishy. :-)
> >
> > I thought the vast majority of transmitters ceased radiating 405 on or
> > around 4th January 1985, unlike the closure of 625 PAL which was a
> > drawn out process over several years.
> No, not at all was done it batches every three months, starting in April
> 1982, and ending in January 1985. I think only a handful were left by Jan
> 85. The Beeb had about 100 sites,

memory says 120

> the IBA had 47, (though most of those were relays) BBC and ITV
> transmitters in the same area were switched off together. For instance,
> BBC Oxford, Hungerford, and Marlborough, the same day as ITV Membury,

> I doubt any captions were possible on the relays though (unless the
> parent was being switched off the same time).

> Take a look at some of the IBA Engineering info progs on You Tube from
> the era.

> Naturally the large population sites were the last to go, CP, Croydon,
> Holme Moss, Emley, Winter Hill etc...
> > I had a look through a couple of ITV 'teletext recoveries' from late
> > 1984 (recovered from VHS tapes with special software), but no sign of
> > any captions hidden in there.
> Well, they were there, I seem to recall the one I saw was on TVS's
> 'regional' sub-pages.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle