|
Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
|
Thread Tools |
15th Nov 2017, 6:54 pm | #1 |
Octode
Join Date: Jan 2014
Location: Oban, Scotland, UK.
Posts: 1,129
|
Colour Wheels etc.
Split from this thread:-
https://www.vintage-radio.net/forum/...d.php?t=141400 I seem to recall experiments that had the placement of two monochrome tubes at 90 degrees and coloured glass over them, then the video images extracted from the on-air colour signal (red and blue?) applied accordingly with the combination producing a 'colour' picture - or is my memory failing me? |
15th Nov 2017, 6:59 pm | #2 |
Heptode
Join Date: Aug 2009
Location: Carshalton, Surrey, UK.
Posts: 735
|
Re: Change your B/W TV into colour?
Hi,
well it seems it was possible in the USA ! http://www.hawestv.com/mtv_FAQ/colrteBasicFAQ.htm but it would make a set much larger due to the colour wheel and would need a lot of electronics.
__________________
Regards Peter B |
15th Nov 2017, 7:29 pm | #3 |
Dekatron
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 4,311
|
Re: Change your B/W TV into colour?
I think Practical Electronics ran a series of articles on converting a black and white set into an 'artistic' sound-to-light display using this technology. The scan circuitry was disconnected and the sound (music) could be used to create linear or Lissajous patterns on the screen which changed colour as the phase between the spinning colour-wheel and the pattern generator electronics varied. I don't recall there being any synch between the two.
Some (most ? all ?) modern domestic digital projectors use an electro-mechanical colour engine I believe. Cheers, GJ
__________________
http://www.ampregen.com |
15th Nov 2017, 7:32 pm | #4 |
Nonode
Join Date: Jan 2008
Location: Milton Keynes, Bucks. UK.
Posts: 2,552
|
Re: Change your B/W TV into colour?
I can't remember the exact year, probably mid 50's or so.
Once a week I used to go to my best mate's house for tea (beans on toast) and also to watch Hop-a-Long Cassidy on their B&W TV (we didn't have a telly until later) and it was during the commercial break that OXO ran a test advert. They showed a picture of a cow and in a square shape on the side of the cow they flashed different patterns, shapes, moving stripes etc and asked you to write on a postcard what 'Colours' you could see. The incentive for sending in the postcard was, when colour TV came to Britain you could be the lucky winner of one !
__________________
When I die, please don't let my Wife sell my collection for the amount I told her I paid for it! |
15th Nov 2017, 7:39 pm | #5 |
Retired Dormant Member
Join Date: Dec 2007
Location: Shropshire, UK.
Posts: 3,051
|
Re: Change your B/W TV into colour?
There was at least one other demonstration of the flickering colour illusion, on Tomorrow's World.
I think I've mentioned here before an occasion when a significant number of viewers reported having seen an image (a bowl of fruit, I think) in correct colours on their monochrome sets. Never explained as far as I know, but presumably another example of this or a similar effect. |
15th Nov 2017, 7:39 pm | #6 | |
Dekatron
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,274
|
Re: Change your B/W TV into colour?
Quote:
Peter |
|
15th Nov 2017, 9:41 pm | #7 | |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,966
|
Re: Change your B/W TV into colour?
Quote:
|
|
15th Nov 2017, 10:08 pm | #8 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,130
|
Re: Change your B/W TV into colour?
Yes, one of the best pieces of evidence of this is the footage of a lunar take-off, where the sequential nature of the colour wheel results in a somewhat psychedelic display.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley) |
15th Nov 2017, 10:44 pm | #9 | |
Dekatron
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 4,311
|
Re: Change your B/W TV into colour?
Quote:
Here's the cover of PE Aug 1968 http://www.vintageradio.me.uk/magazi...ics1968Aug.JPG which consists of some screen shots. Cheers, GJ
__________________
http://www.ampregen.com |
|
15th Nov 2017, 11:04 pm | #10 |
Retired Dormant Member
Join Date: Dec 2007
Location: Shropshire, UK.
Posts: 3,051
|
Re: Change your B/W TV into colour?
I remember reading these articles.
Although as a youngster I was more happy-go-lucky about safety than I am these days, even then it seemed rather a risky contraption in a number of ways! I've always been interested in lightshows and the like, so found it a fascinating idea nevertheless. I was privileged to witness a demonstration of mechanical field-sequential TV as part of a lecture on colour TV prior to its appearance in this country. My memory is of something noisy and impractically flickery, but then I'm one of those people who can't watch modern DLP projectors either. |
16th Nov 2017, 12:33 am | #11 |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,203
|
Re: Change your B/W TV into colour?
But some artefacts if you blink your eyes or move your head rapidly. Just try it with any modern projector (which has presumably a higher field frequency so less artefacts).
|
16th Nov 2017, 9:12 am | #12 | |
Dekatron
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,274
|
Re: Change your B/W TV into colour?
Quote:
Peter Last edited by peter_scott; 16th Nov 2017 at 9:19 am. |
|
16th Nov 2017, 9:49 am | #13 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
|
Re: Change your B/W TV into colour?
Peter, all I can say is WOW! John.
|
16th Nov 2017, 10:17 am | #14 |
Dekatron
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,274
|
Re: Change your B/W TV into colour?
I took that picture off the screen of the Gray Research Monitor at ETF. Steve McVoy very kindly took quite some time to get it working for me and as Maarten points out, there are artifacts with movement etc but I was very impressed by the results.
http://www.earlytelevision.org/gray_monitor.html Peter |
16th Nov 2017, 10:58 am | #15 |
Nonode
Join Date: Feb 2005
Location: Worcestershire, UK.
Posts: 2,534
|
Re: Colour Wheels etc.
Here are the colour wheels I made many years ago for an NBTV project. The other pic shows how they were mounted behind the Nipkow disc for stereoscopic colour.
A separate similar arrangement was needed at the camera. Steve |
16th Nov 2017, 11:04 am | #16 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Colour Wheels etc.
I love that ingenious tensioner!
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
16th Nov 2017, 11:23 am | #17 |
Nonode
Join Date: Feb 2005
Location: Worcestershire, UK.
Posts: 2,534
|
Re: Colour Wheels etc.
Tyre inner tube rubber as the 'spring' !
|
16th Nov 2017, 12:30 pm | #18 |
Octode
Join Date: Jan 2014
Location: Oban, Scotland, UK.
Posts: 1,129
|
Re: Colour Wheels etc.
The technique I 'think' I saw used two screens at right angles to each other with a 'deflection' plate (clear glass) in between them. I'm almost certain it was in an old issue of Television Magazine.
A red and green signal were passed straight to each mono tube and the combination produced a 'colour' picture when viewed from the right direction - obviously limiting the number of viewers! - and not full colour by any means (although there may be a better combination of mixing colours to get a suitable image?). It would also have required the reversal of scan for one of the tubes. Did anyone else see such a project advertised? My wife tells me she knew (as a young child) someone in the Kingussie area (central Scotland) that made a 'colour' TV when they first came out but she doesn't know any more details of the process they used - her comment just reminded me of the example I state above. |
16th Nov 2017, 1:35 pm | #19 |
Dekatron
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,274
|
Re: Colour Wheels etc.
The two colour system sounds like Baird's.
Peter Last edited by peter_scott; 16th Nov 2017 at 2:05 pm. |
16th Nov 2017, 1:49 pm | #20 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,724
|
Re: Change your B/W TV into colour?
And doubly impressive when you consider that Judy Garland was being photographed by a Technicolor camera loaded with monochrome film.
__________________
-- Graham. G3ZVT |