240 line Baird system ?

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240 line Baird system ?

Postby Harry Dalek » Tue Sep 05, 2017 8:24 pm

I am not sure about this ? it looks made up to me ...
http://www.markmcm.co.uk/apfs/apfs_pres ... _baird.htm
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 240 line Baird system ?

Postby Dave Moll » Wed Sep 06, 2017 5:08 pm

As far as I know, once the BBC chose the EMI 405-line service, that was the end of the Baird 240-line transmissions.
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Re: 240 line Baird system ?

Postby Andrew Davie » Wed Sep 06, 2017 5:56 pm

The kerning and spacing of the fonts suggests computer-generated to me. I bet I can find the font, actually... watch this space.
Probably the font wasn't even in existence in 1939...
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Re: 240 line Baird system ?

Postby Harry Dalek » Wed Sep 06, 2017 7:24 pm

Andrew Davie wrote:The kerning and spacing of the fonts suggests computer-generated to me. I bet I can find the font, actually... watch this space.
Probably the font wasn't even in existence in 1939...


Yes boys it looked modern mock up to me as well and blurring and all of the graphics as you think Andrew ...got me interested why he has such a nice collection of these things but the Baird one is fake ...saying baird 240 system was transmitted along side the EMI till world war 2 broke out makes it worse ...wishful thinking ?
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 240 line Baird system ?

Postby Harry Dalek » Wed Sep 06, 2017 8:32 pm

Interesting if the next week Baird got 4 days why did he only get 2 days out of the week mmm
I wonder if the laundry program twice that first day killed the 240 line service :roll:
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tv_schedule.gif
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 240 line Baird system ?

Postby Steve Anderson » Wed Sep 06, 2017 8:41 pm

Yes, it's all too clinical even with the superimposed defects - and why hasn't this surfaced before?

However, there was a 240-line Baird standard as detailed in the jpg attached. How far this got and whether it was ever transmitted I'll leave to the historians. Unless this document is also a fake, but it's been around for a few years so I would doubt it's come from the same source. I'm sure I've posted this before here a few years back.

I note that someone a few years back had an item on 240-line TV in the newsletter, I presume it may have been to this standard.

From the data in the jpg I worked out the following...

Baird 240-line system.

240 lines, 25fps, no interlace, 6kHz line rate.

Sync amplitude =40% of composite signal.
Single broad frame sync of 12 lines = 2ms, frame blanking of 20 lines = 3.333ms.

Line period = 166.7us, line sync is 8% line-time = 13.33us.
Active line video = 150us.
Line blanking is 10% of line time = 16.67us, no front porch. (Same with vertical).

Aspect ratio unknown...but appears to be 4:3.

At 4:3 aspect ratio active video needs a minimum of 293.3 pixels/line, = 325.9 pixels/line inc. blanking etc.


At around this time Baird's development of CRT displays was on-going, but how he generated the source signals beyond test cards is open to discussion.

Steve A.

Oh yes! I really want to watch a program on ironing my laundry twice in one day! If anyone equates ironing with being a hobby they need their bumps felt!

http://www.urbandictionary.com/define.p ... mps%20Felt
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240line (Large).JPG
240line (Large).JPG (81.84 KiB) Viewed 332 times
52c2015cb82a3ce1b7f0b8d674364a90--retro-funny-retro-humor.jpg
52c2015cb82a3ce1b7f0b8d674364a90--retro-funny-retro-humor.jpg (45.64 KiB) Viewed 327 times
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Re: 240 line Baird system ?

Postby Harry Dalek » Wed Sep 06, 2017 8:58 pm

i found this reading up
The Baird and EMI transmitting times must of got changed i read there was a fire and transmitting problems on the Baird side ..
The 243 line standard was an electronic system that EMI intended to use to compete with Baird. 243 = 3 X 3 X 3 X 3 X 3 Change the last figure to 5 and we get 405.
On the laundry program i can't say is that idea has never been repeated wonder why? :lol:
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Screen 00011.jpg
Screen 00011.jpg (40.99 KiB) Viewed 326 times
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 240 line Baird system ?

Postby Andrew Davie » Wed Sep 06, 2017 9:52 pm

OK, this bit is interesting... looking at the "competition" guide, and noting one of the programs for Baird's system was "Movietone Magic Carpet" I found a (french) version of this show on YouTube (obviously a period piece, say late '30s). At about 15 seonds it has some text which, as far as I can tell... is a VERY similar font to the original website "screenshots". I no longer think that the font is a modern one, but instead that it's reasonable to claim this as a 1930s font.


youtu.be/Am6DoLn7_pM

Comparison screenshots... "fake" first...

reich.jpg
reich.jpg (104.71 KiB) Viewed 324 times


and now the contemporary "magic carpet"...

magiccarpet.jpg
magiccarpet.jpg (95.23 KiB) Viewed 324 times
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Re: 240 line Baird system ?

Postby Dave Moll » Thu Sep 07, 2017 5:24 pm

Certainly, those two typefaces are very similar, though not identical. Notably, the balance of the loops in the capital "B" is different, and the ascenders on
"d", "h" and "l" are longer in the French version, whereas they are the same height as "i", "t" and capital letters in the "Baird" text".
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Re: 240 line Baird system ?

Postby Harry Dalek » Thu Sep 07, 2017 7:10 pm

Its ironic one of the dual 240 405 line crt sets is a Baird i like the look of the Scophony mechanical set my self.
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Harry Dalek
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