Audio Precision System One Dual Domani Measuirement Systems

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

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.

--
J. P. Gilliver. UMRA: 1960/

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.

--
Geoffrey S. Mendelson,  N3OWJ/4X1GM
My high blood pressure medicine reduces my midichlorian count. :-(

In message , Geoffrey S. Mendelson writes: []

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).

--
J. P. Gilliver. UMRA: 1960/

405:

1936 - 1939

1946 - 1985

625:

1964 - 2012 (BBC2 only until Nov. 69)

--

Terry

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

d

In message , hwh writes

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.

--
Clive

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.

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

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.

That is an urban legend and just not true.

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.

--
*It was all so different before everything changed.

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

From

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.

"Geoffrey S. Mendelson" wrote

No idea what that's supposed to mean!

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.

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.

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.

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.

What's TV?

Kind regards

Peter Larsen

The Idiot's Lantern, The Haunted Fishtank, Radio with Pictures,

Hope this helps ;) Ron

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.

--
Clive

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.

Rod.

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