17th May 2018, 12:48 am | #61 |
Dekatron
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Re: TV system differences?
Here's a question that's just popped into my head.
Up until the date when analog (sic) ceased in the US, did "Never Twice the Same Color" sets still have a hue control, or had some technological advance made it redundant? Perhaps different hue setting could be stored on a per-channel basis I ask because in modern sets, contrast, brightness, saturation etc are hidden away in a menu, and tend to be set & forget as far as the viewer is concerned.
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17th May 2018, 3:20 am | #62 |
Nonode
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Re: TV system differences?
The introduction of the vertical interval reference signal (VIRS) largely did away with the need for interchannel hue adjustments on NTSC receivers. For VIRS background, see: http://tig.colorist.org/pipermail/ti...ry/010331.html. I think that hue controls were still provided, perhaps to cover transmitters not using VIRS, and because to some extent they were expected.
I used a Fisher PC-225 high-resolution receiver-monitor in the USA from 1986 through 1996, and I don’t recall ever using the hue control apart from playing around with it when it was new. I haven’t kept the manual, unfortunately – it went with the receiver to its next user in 1996. Even the previous fairly old rental TV that I used during 1985 did not require regular hue adjustments. So it would appear that VIRS did a pretty good job. Cheers, |
17th May 2018, 7:40 am | #63 | |
Heptode
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Re: TV system differences?
Quote:
See attachment. This set also exists in 625 only version (i.e. not having the standards selection switch on the left side). Jac Last edited by Jac; 17th May 2018 at 8:09 am. |
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17th May 2018, 8:01 am | #64 |
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Re: TV system differences?
Also the little Sony 9-90UM version has UHF and VHF and 819 as well as 625.
If it's anything like the 405/625 version then you can select any permutation of carrier frequency and timebase. Peter |
17th May 2018, 9:57 am | #65 |
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Re: TV system differences?
Lest we forget , the 625 system was extended for 16:9 broadcasting in the UK only - from the early 90's? And remembering the earlier Pal plus too (C4 and Granada only though?).
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17th May 2018, 1:42 pm | #66 | |
Nonode
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Re: TV system differences?
Quote:
This was one reason most of the Eastern European countries using SECAM switched to PAL in the 1990s as the cost of buying new infrastructure was cheaper for PAL. I presume SCART sockets were an early addition to French TVs to get round some issues with creating a SECAM output in early VCRs & home computers. |
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18th May 2018, 7:41 am | #67 |
Heptode
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Re: TV system differences?
No SCART was nothing to do with that. Recording secam is much simple than PAL as jitter on playback did not affect the colour. French VCRs simply filtered off the colour and divided the frequency by 4 to record and multiplied it by 4 on playback. By the time computers came along French TVs could decode both PAL and secam as they worked by transcoding secam to PAL and then decoding that.
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18th May 2018, 10:21 am | #68 | |
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Re: TV system differences?
Quote:
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18th May 2018, 1:41 pm | #69 | |
Nonode
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Re: TV system differences?
Quote:
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18th May 2018, 10:29 pm | #70 |
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Re: TV system differences?
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18th May 2018, 11:46 pm | #71 |
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Re: TV system differences?
Purely as an aside but regarding my posts at 31* and 54*, the Bexhill Observer reports today that Hastings [5 miles away] has put in a bid to accomodate one of the proposed three re-locations for the Channel Four organisation. This is based on J L Baird living there in 1922 [briefly before returning to London] and blowing up the Shopping Arcade. They are always quick to capitalise on that incident.
Unfortunately, Bexhill gets a bad deal generally in terms of local government representation. Hastings has a John Logie Baird Wetherspoons pub [there are a few around the UK]. Now, Bexhill has a Wetherspoons as well but I couldn't persuade them to "twin" it in some way despite JLB living here for seven years and dying in 1946, just when he would have demonstrated an innovative electronic colour tv system. "You don't know what you've got till it's gone!" Jony Mitchell. Dave W PS. I notice that my posts have now reached 3,500. Please don't be fooled [I'm sure you aren't]. This does not represent any technical competence or false modesty. i just happen to have an eclectic [magpie brain] interest beyond the technology, nothing more. If I devoted as much time to the soldering iron, I would merely be trying to catch up [in a futile way] with those those on here that I regard as entirely gifted in terms of restoration work. I wouldn't manage it-"too many other interests". I once had a book on Cybernetics with a cartoon of Leonardo Da Vinci. His job application photo changes to gloom when it's stamped with that phrase. It's there were any similarity ends of course! Last edited by dave walsh; 19th May 2018 at 12:13 am. |
19th May 2018, 12:04 am | #72 |
Hexode
Join Date: Mar 2013
Location: Coventry, West Midlands, UK.
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Re: TV system differences?
Indeed. In spite of which the local council constructed these flats with a single aerial output socket for both VHF and UHF.
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19th May 2018, 12:39 am | #73 |
Heptode
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Re: TV system differences?
Not quite. MESECAM (Middle East secam), also called special secam, or secamDDR was a mod to PAL VCRs to enable them to record secam. It did not work as well as a true secam VCR but was used in areas where both secam and PAL was receivable.
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21st May 2018, 12:31 am | #74 | |
Hexode
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Re: TV system differences?
Quote:
I was referring to my memories (1975, 1977) of poor picture quality, watching various programmes on receivers in the London area, and comparing to viewing experiences with Australian free to air 625 TV, and industrial 819 line Air Traffic Control (also Australian) radar displays (US Conrac chassis). But ... after now watching some You Tube clips of old UK 405 programmes, and allowing for "variables", I have to admit that my viewing experiences must have been seriously and adversely affected by TV set deficiencies. So... I withdraw my earlier comments about poor 405 programme picture quality. |
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21st May 2018, 11:19 am | #75 |
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Re: TV system differences?
I always thought that 405 was finally phased out because the line structure was becoming intrusive on the ever larger screens. The picture quality was otherwise acceptable to the general public.
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21st May 2018, 1:59 pm | #76 |
Octode
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Re: TV system differences?
What was the final decision to pull the plug on the 405 line system in 1984? I was wandering that as the transmitter infrastructure was still in place and working when switched off whether we could have had a few more years of 405 transmission (may be up to the 1990's) I think we should have had a much longer transition period before 625 analogue was switched off in 2012.
Christopher Capener
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21st May 2018, 3:47 pm | #77 |
Dekatron
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Re: TV system differences?
By 1984 all the 405-line transmissions were duplicates of what was available on 625 lines, so I imagine the main factors were getting rid of all the additional equipment (standards converters and VHF transmitters), and freeing up the VHF spectrum so that it could be sold off to other potential users. Not to mention allowing manufacturers to cease production of dual-standard televisions.
I seem to recall that the final switch-off in 1984 was somewhat later than intended because of the number of viewers with 405-only televisions still in use. I think the demise of 405 lines was set in motion with the decision to make BBC2 a 625-line only service
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21st May 2018, 5:31 pm | #78 |
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Re: TV system differences?
Yes Dave, I remember the surprising number of people who, despite the publicity, didn't realise what was going on. Some thought the telly had failed when the screen went blank or complained to the Broadcasters. I suppose it was no use ringing BBC2 or Channel 4 [on air from 1982] even if they knew what they were
I think the later change to Digit Al went a bit smoother but there was some sharp practise in that some viewers thought they would HAVE to buy a new set and weren't always told about the Digi Box option by retailers. I see that the process was from 2007 to October 2012. The final one might have been Ramsbottm as we were one of the last communities to get a transponder [or whatever it was] squeezed into the the Rammy Relay next to the remains of Grant's Tower-now partially restored by the new owners at the Farm. I have tried to promote the notion of a Cable Car across the valley to Peel Tower [still standing] but a prophet is always without honour in his own country! Dave W Last edited by dave walsh; 21st May 2018 at 5:49 pm. |
21st May 2018, 8:03 pm | #79 | |
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Re: TV system differences?
Quote:
We were a young Married couple with a big mortgage yet the rest of the family expected the only Techie in the family to resolve the problem. Resolved with a 1500 bought second hand ex rental from a PW advertiser who's catchline was something like the largest TV graveyard in the North. Just stock faults I think it had an Ultra Badge so close to Carradon excellent picture on a set top Aerial. When I was at PCFE in the Mid 70's the B&W Test subject was the 1500 so I knew it pretty well. Many Brownie points with small money spent. Cheers Mike T
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25th May 2018, 1:01 am | #80 |
Pentode
Join Date: Mar 2016
Location: Champaign, Illinois, USA.
Posts: 227
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Re: TV system differences?
In the US color sets retained a physical hue control until ICs replaced
discrete transistors. However, it slowly moved to a hidden place. Even my current 55 inch Sony LED set actually has a real hue control in the hidden service menu ... it rotates U and V. And the correct setting is not how it came set from the factory, though it has remained perfectly stable. I can't get color right without it. One suspects that Sony uses "test subject panels", different for each country, to set everything "to local taste" instead of correct. |