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Re: Audio Precision System One Dual Domani Measuirement Systems

J

J. P. Gilliver (John)

hwh said:
Erm, 405 started before the war and was alone until 1964? Then it
continued for another 20 years?

gr, hwh

OK, so I was wrong about the second period being longer than the first
(though the number of receivers near the beginning of the first period
was tiny). Don't include the war itself - it was turned off during that.
(No TV!)

No, I've looked it up: UK 1936-1985 (fully from 1937, but not during the
war: 1939-9-1, back after in fact, in 1946); Eire 1961-1982 (they had
625-line from 1962). [Hong Kong 405: 1957-1973. Other countries,
experimental only, in 1939.] All from
http://en.wikipedia.org/wiki/405_line.

I was mainly responding to the person who said that in theory USA could
still have analogue TV until (I think he said) 2015, but had switched as
soon as they could; UK, in contrast, keeps old systems going a Long
Time. Less so nowadays - most early digital terrestrial TV boxes will be
killed off by the switchover (a change to the encoding is coming in at
the same time), and those will only have been in use a comparatively low
number of years.
 
G

Geoffrey S. Mendelson

hwh said:
Erm, 405 started before the war and was alone until 1964? Then it
continued for another 20 years?

Someone said the last two years of 405 line signals were generated by an unusal
method, I think the word they used was "endearing". What was it?

BTW, the BBC shut down TV broadcasts in for World War II, and resumed
them at the exact point in the same broadcast after the war. :)

Geoff.
 
J

J. P. Gilliver (John)

In message <[email protected]>, Geoffrey S.
Mendelson said:
Someone said the last two years of 405 line signals were generated by an unusal
method, I think the word they used was "endearing". What was it?

That was me. It was in Eire. For the last few years they, like the BBC,
made programmes in 625 lines, and used a digital standards converter to
produce the 405-line signals for those with old sets. Towards the end of
405 line in Eire (last 5 years I think), their standards converter broke
down, and rather than fix it they used a 405 line camera pointed at a
625 monitor (more or less).
 
T

Terry Casey

Erm, 405 started before the war and was alone until 1964? Then it
continued for another 20 years?

gr, hwh

405:

1936 - 1939
1946 - 1985

625:
1964 - 2012 (BBC2 only until Nov. 69)
 
D

Don Pearce

In message <[email protected]>, Geoffrey S.


That was me. It was in Eire. For the last few years they, like the BBC,
made programmes in 625 lines, and used a digital standards converter to
produce the 405-line signals for those with old sets. Towards the end of
405 line in Eire (last 5 years I think), their standards converter broke
down, and rather than fix it they used a 405 line camera pointed at a
625 monitor (more or less).

I know all about telecine, but teletele? That's a new one.

d
 
C

Clive

hwh said:
Erm, 405 started before the war and was alone until 1964? Then it
continued for another 20 years?
I know colour came in, in 1967 on BBC2 but I thought that broadcasting
on BBC2 started in 1962. I know it was never on 405 lines.
 
J

J G Miller

AFAIK, we haven't had analog TV broadcast anywhere in the US since June
2009.

That just ain't true.

What you are forgetting (or perhaps never heard of because you prefer
giving money to the cable company each month) is that Class A, Low Power
TV, and Repeater TV stations were not required to go digital only in
June 2009.

<http://www.fcc.GOV/guides/dtv-transition-and-lptv-class-translator-stations>

Nonetheless, your most local station of this type, formerly W66BV Detroit
has made the transition to digital.

<http://en.wikipedia.ORG/wiki/W47DL-D>

Incidentally, does your cable TV company include this station on the basic tier?

And an interesting new development in the Detroit market, is that the station
licensed to Ann Arbor (formerly analog UHF channel 31) is going to start
broadcasting with a high power signal on UHF channel 50 (which was vacated
when WKBD, now on UHF channel 14, stopped analog transmissions) from the
Southfield tower site, and will cease transmitting from Ann Arbor.

<http://www.michiguide.COM/archives2012/2012/01/ion-television-fires-up-new-wp.html>
 
D

Dave Plowman (News)

Towards the end of
405 line in Eire (last 5 years I think), their standards converter broke
down, and rather than fix it they used a 405 line camera pointed at a
625 monitor (more or less).

Surprised they could find a working one. In the UK, a 405 line camera
would have been B&W, and all those in use were colour long before 405 got
switched off.
 
J

J G Miller

I know colour came in, in 1967 on BBC2 but I thought that broadcasting
on BBC2 started in 1962. I know it was never on 405 lines.

From <http://www.hywel.org.UK/bbc2launch/>

QUOTE

When BBC2 launched on April 20th 1964, ...


UNQUOTE

Remember also that BBC-2 was the first regular TV service transmitted in
UKofGB&NI on UHF channels.

So not only did it require a new TV to be able to tune to UHF and demodulate
the signal to 625 lines, it also needed a separate antenna to the VHF Band I
and VHF Band III antennas being used to receive the BBC television service
and the independent (commercial) television service.
 
D

David Looser

Geoffrey S. Mendelson said:
Someone said the last two years of 405 line signals were generated by an
unusal
method, I think the word they used was "endearing". What was it?
No idea what that's supposed to mean!
BTW, the BBC shut down TV broadcasts in for World War II, and resumed
them at the exact point in the same broadcast after the war. :)
Not really. The last actual programme pre-war was a transmission of a Mickey
Mouse film; post war TV started with a transmission of the same film. So if
you'd been glued to your TV from Sept 1939 to June 1946 you'd have seen the
film twice, thus not "resumed at the exact point"

David.
 
D

David Looser

J. P. Gilliver (John) said:
In message <[email protected]>, Geoffrey S. Mendelson


That was me. It was in Eire. For the last few years they, like the BBC,
made programmes in 625 lines, and used a digital standards converter to
produce the 405-line signals for those with old sets. Towards the end of
405 line in Eire (last 5 years I think), their standards converter broke
down, and rather than fix it they used a 405 line camera pointed at a 625
monitor (more or less).

That technique was used used by the BBC from the early 1950s until the mid
1960s to convert to and from continental standards. I've never heard it
called "endearing" before, this bizzare word must be Irish!

David.
 
D

David Looser

J G Miller said:
From <http://www.hywel.org.UK/bbc2launch/>

QUOTE

When BBC2 launched on April 20th 1964, ...


UNQUOTE

Remember also that BBC-2 was the first regular TV service transmitted in
UKofGB&NI on UHF channels.

So not only did it require a new TV to be able to tune to UHF and
demodulate
the signal to 625 lines, it also needed a separate antenna to the VHF Band
I
and VHF Band III antennas being used to receive the BBC television service
and the independent (commercial) television service.

Also BBC2 used -ve vision modulation and FM sound (sound carrier 6MHz above
the vision carrier), whereas the 405-line services used +ve vision
modulation and AM sound (sound carrier 3.5MHz below the vision carrier).
Dual-standard TVs were a triumph of compromise! (Dual-standard TVs were also
needed between Nov 1936 and February 1937 to cope with the Baird 240-line
system as well as the Marconi/EMI 405-line one. But in this case it was only
the timebases that needed to be switched, all RF & sound issues remained the
same).

David.
 
J

J G Miller

So if you'd been glued to your TV from Sept 1939 to June 1946
you'd have seen the film twice, thus not "resumed at the exact point"

And complain that all the BBC television service does is
show repeats. ;)
 
D

David Looser

J G Miller said:
And complain that all the BBC television service does is
show repeats. ;)

The BBC started the way they meant to go on ;-) the second scheduled
programme was a repeat of the first! (the opening ceremony, transmitted
first on the Baird system then repeated on the Marconi/EMI system). And in
August 1936 before the service had officially started they transmitted the
same variety programme (live) twice a day for ten days for the benefit of
trade stands at Radio Olympia.

David.
 
C

Clive

J G Miller <[email protected]> said:
From <http://www.hywel.org.UK/bbc2launch/>
QUOTE
When BBC2 launched on April 20th 1964, ...
UNQUOTE
Remember also that BBC-2 was the first regular TV service transmitted in
UKofGB&NI on UHF channels.
So not only did it require a new TV to be able to tune to UHF and demodulate
the signal to 625 lines, it also needed a separate antenna to the VHF Band I
and VHF Band III antennas being used to receive the BBC television service
and the independent (commercial) television service.
To add to that it also had FM sound instead of the AM used on 405 and
negative going luminance instead of the positive going luminance of 405
lines with the advantage that interference which blighted 405 with
little white "fishes" it had little black fishes and were normally out
of sight.
 
I

Ian Jackson

In message said:
Actually, it's a very old one. Before they invented clever electronic ways
of converting television standards, that's the way it was done. Even in the
1970s, although by that time there were electronic convertors for 625 lines,
the only equipment the BBC had for dealing with 819 line signals was an
optical convertor, which amounted in essence to a camera pointing at a
monitor. I'm sure the Irish broadcasters could have done something more
elegant, but maybe they didn't think it was worth the expense.
The UK 405-line system was almost certainly kept going for far longer
than it really needed to be. There was probably only a handful of people
who could not receive the 625-line service. At the time, I recall that
many of us said that it would be cheaper simply to buy that last little
old lady, living in a remote valley in the middle of nowhere, a new TV
set and aerial.
 
T

Terry Casey

Eire 1961-1982 (they had 625-line from 1962).

I was in Ireland in August 1961, before RTE started.

On the last day, I visited the village post office where the following
conversation took place with the elderly post mistress:

She: "Would you mind me asking how much you're after paying for the
television licence in England?"

Me: "Four pounds and a pound for the wireless licence"

She (looking rather pleased with herself) "Ah! We're only after paying
the seventeen shillings and sixpence for the wireless licence and we
don't have the television licence!"

On our way home the following day I spotted the headline on the evening
paper:

£4 TV LICENCE FROM JANUARY
Wireless licence goes up to £1

I've always wished I could have seen the look on the old lady's face
when she saw that!
 
H

hwh

The UK 405-line system was almost certainly kept going for far longer
than it really needed to be. There was probably only a handful of people
who could not receive the 625-line service. At the time, I recall that
many of us said that it would be cheaper simply to buy that last little
old lady, living in a remote valley in the middle of nowhere, a new TV
set and aerial.

Maybe it would have been better to have one 625 line network on VHF,
like most other countries used until analog closedown.
Of course going from 405 to 625 would have meant ther was no room for
two networks there.

gr, hwh
 
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