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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

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Old 17th May 2018, 12:48 am   #61
rambo1152
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Default 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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Old 17th May 2018, 3:20 am   #62
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Default 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 donít recall ever using the hue control apart from playing around with it when it was new. I havenít kept the manual, unfortunately Ė 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.


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Old 17th May 2018, 7:40 am   #63
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Default Re: TV system differences?

Quote:
Originally Posted by Richard_FM View Post
I did wonder if any dual standard 625 / 819 line sets were made for the French market.
Ekco made a version of the TX275 that would do 625 and 819.
See attachment.

This set also exists in 625 only version (i.e. not having the standards selection switch on the left side).

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Old 17th May 2018, 8:01 am   #64
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Default 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.

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Old 17th May 2018, 9:57 am   #65
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Default 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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Old 17th May 2018, 1:42 pm   #66
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Originally Posted by Radio Wrangler View Post
Standards conversion and SECAM was a bit of a joke.

It turned out that SECAM was the very devil to mix and do the usual video tricks to because of the delays needed. So programmes were made in PAL and only at the last stage converted to SECAM for transmission.

Supreme Effort indeed!

David
Yes I've heard the studio equipment had to be PAL or else covert the signal for mixing. Later one RGB equipment were used & SECAM was encoded down the line.

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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Old 18th May 2018, 7:41 am   #67
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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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Old 18th May 2018, 10:21 am   #68
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Yes I've heard the studio equipment had to be PAL or else covert the signal for mixing. Later one RGB equipment were used & SECAM was encoded down the line.

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.
I think it more likely signals were originated in Y,U,V then transcoded to SECAM at the appropriate point in the signal chain. RGB is a bit of a nightmare to be honest, even the smallest variation in amplitude giving a colour cast to the resulting pictures. I know of only one broadcast kit manufacturer who made any significant amounts of SECAM kit - Michael Cox and his associated companies.
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Old 18th May 2018, 1:41 pm   #69
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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.
OK I didn't realise that, I was getting it confused with MESECAM which does some trickery to convert SECAM to PAL for recording IIRC.
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Old 18th May 2018, 10:29 pm   #70
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In fact both 525/60 and 625/50 live on into the digital era - SD services in the respective territories continue to use them

J
They go by the names 480i and 576i respectively.
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Old 18th May 2018, 11:46 pm   #71
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Default 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!

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Old 19th May 2018, 12:04 am   #72
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Default Re: TV system differences?

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UK dual standard TV sets had both VHF and UHF tuners in them, along with the need for two antennae (usually opposite polarisations) and downleads.
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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Old 19th May 2018, 12:39 am   #73
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Quote:
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Quote:
Originally Posted by winston_1 View Post
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.
OK I didn't realise that, I was getting it confused with MESECAM which does some trickery to convert SECAM to PAL for recording IIRC.
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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Old 21st May 2018, 12:31 am   #74
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Originally Posted by paulsherwin View Post
Do you mean that UK 405 productions looked bad on the Australian system? That's because they would have been 16mm telerecordings. The 405 system gave very good results on the 405 TVs of the day. It was abandoned for reasons of standardisation within Europe, not because it performed poorly.
Sorry re late reply, but just home after flitting around Africa.

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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Old 21st May 2018, 11:19 am   #75
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Default 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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Old 21st May 2018, 1:59 pm   #76
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Default 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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Old 21st May 2018, 3:47 pm   #77
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Default 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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Old 21st May 2018, 5:31 pm   #78
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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

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Old 21st May 2018, 8:03 pm   #79
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Default Re: TV system differences?

Quote:
Originally Posted by Dave Moll View Post
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
Agree with Dave's assesment my wifes Grandparents who live in the Shadow of Carradon only had a 50's 405 TV I think it was a Murphy we got a bit of a cry for help when 405 was switched off and suddenly no Corrie.

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.

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