TV Home Forum

50 years of Test Card F

(June 2017)

This site closed in March 2021 and is now a read-only archive
JW
JamesWorldNews
deejay posted:
I think Carol Hersee, the girl with the clown, was interviewed on BBC South Today some years ago, presumably for a similar anniversary. I suppose there's a chance that could happen again. Carol was the daughter of one of the engineers that designed the card AIUI. They needed a colour photograph as skintone is quite tricky to line up properly. The photo is still incorporated into the current HD testcard which is still shown on BBC TWO as part of the overnight barker. I believe it's officially known as Testcard X and comes accompanied with a 5.1 sound test sequence. Testcard X replaced Testcard W, which was the first 16:9 aspect ratio card.

Some years ago, they re-positioned the photograph so the X on the blackboard is at the centre of the screen.


Forgive my ignorance: what's an overnight barker?
RK
Rkolsen
JamesWorldNews posted:
deejay posted:
I think Carol Hersee, the girl with the clown, was interviewed on BBC South Today some years ago, presumably for a similar anniversary. I suppose there's a chance that could happen again. Carol was the daughter of one of the engineers that designed the card AIUI. They needed a colour photograph as skintone is quite tricky to line up properly. The photo is still incorporated into the current HD testcard which is still shown on BBC TWO as part of the overnight barker. I believe it's officially known as Testcard X and comes accompanied with a 5.1 sound test sequence. Testcard X replaced Testcard W, which was the first 16:9 aspect ratio card.

Some years ago, they re-positioned the photograph so the X on the blackboard is at the centre of the screen.


Forgive my ignorance: what's an overnight barker?


A barker by definition is a channel of digital signage for advertisements. In this context they probably mean promotions for upcoming shows.

In the US one example of a Barker channel is when you go onto Comcast (Xfinity) OnDemand. They have the hot movies available for rent, free TV shows to discover or catch-up on demand, advice on your subscription or try to upsell you to a premium cable package.
IS
Inspector Sands
A barker is basically a loop promoting the channel which is used in its downtime or before launch. They're called barkers because things like circuses and funfairs used to employ people called barkers to entice customers in:
https://en.wikipedia.org/wiki/Barker_(occupation)


Current examples I can think of are the 'This is BBC Two' loop overnight and the ones on CBBC and CBeebies first thing in the morning
Last edited by Inspector Sands on 1 July 2017 7:39am
MA
Markymark
Markymark posted:
JasonB posted:
If anything we might get a small package on BBC Breakfast marking the occasion. Unless we get treated to a sting of some kind.


If BBC Breakfast attempt anything I'll be watching with trepidation. I can almost hear the inaccuracies and misconceptions in my head


I take it all back. Quite a good feature on BBC Breakfast this morning, they had someone on who knew what she was talking about.

She quite correctly made the point we beat Germany to have the first colour service in Europe. Would have been nice to have pointed out PAL was a German developed and patented system, but otherwise 9.5 out of 10
DP
D.Page
Markymark posted:
PAL was a German developed and patented system, but otherwise 9.5 out of 10


Yes, Telefunken were the guys. Worth noting, though, that much of the basis of PAL came from NTSC, so when you say "developed", important to make this clear, I think.
MA
Markymark
D.Page posted:
Markymark posted:
PAL was a German developed and patented system, but otherwise 9.5 out of 10


Yes, Telefunken were the guys. Worth noting, though, that much of the basis of PAL came from NTSC, so when you say "developed", important to make this clear, I think.


Yes ! It was the switching of the chroma sub-carrier p hase every a lternate l ine (hence the name !) that was the key. (Hue errors were converted into saturation increases (or decreases) which the human eye is far less sensitive to. Some Japanese TV manufacturers circumvented the need to pay AEG Telefunken the patent licence, by not having the one line (64 us) delay-line in the TV, and instead had an NTSC style hue control, for the manual correction of the hue (Thus negating the whole point of PAL !)
NG
noggin Founding member
Markymark posted:
D.Page posted:
Markymark posted:
PAL was a German developed and patented system, but otherwise 9.5 out of 10


Yes, Telefunken were the guys. Worth noting, though, that much of the basis of PAL came from NTSC, so when you say "developed", important to make this clear, I think.


Yes ! It was the switching of the chroma sub-carrier p hase every a lternate l ine (hence the name !) that was the key. (Hue errors were converted into saturation increases (or decreases) which the human eye is far less sensitive to. Some Japanese TV manufacturers circumvented the need to pay AEG Telefunken the patent licence, by not having the one line (64 us) delay-line in the TV, and instead had an NTSC style hue control, for the manual correction of the hue (Thus negating the whole point of PAL !)


They still had the delay line - but used it to repeat the previous line's chroma didn't they - so avoiding phase alternation aspect of the patent? Effectively they created an-NTSC-like chroma signal by replacing the lines that were phase alternated by repeating the previous line so all the lines presented to the decoder were in the same phase, like NTSC.

If they'd just ditched the delay line they'd have had to have used Simple PAL - which would still require the patent?
MA
Markymark
noggin posted:
Markymark posted:
D.Page posted:

Yes, Telefunken were the guys. Worth noting, though, that much of the basis of PAL came from NTSC, so when you say "developed", important to make this clear, I think.


Yes ! It was the switching of the chroma sub-carrier p hase every a lternate l ine (hence the name !) that was the key. (Hue errors were converted into saturation increases (or decreases) which the human eye is far less sensitive to. Some Japanese TV manufacturers circumvented the need to pay AEG Telefunken the patent licence, by not having the one line (64 us) delay-line in the TV, and instead had an NTSC style hue control, for the manual correction of the hue (Thus negating the whole point of PAL !)


They still had the delay line - but used it to repeat the previous line's chroma didn't they - so avoiding phase alternation aspect of the patent? Effectively they created an-NTSC-like chroma signal by replacing the lines that were phase alternated by repeating the previous line so all the lines presented to the decoder were in the same phase, like NTSC.

If they'd just ditched the delay line they'd have had to have used Simple PAL - which would still require the patent?


Well now, having read up this morning on this Telefunkun did unsuccessfully try and sue Sony for what they called a PAL-S decoder, using as you say a delay line to repeat the last line of chroma

http://www.radiomuseum.org/forum/45_years_anniversary_of_walter_bruchs_pal_color_television.html

(Scroll down to almost the end, 'Sony's Special Way' )
LS
LoganStuff
BBC One had a quick nod to Test Card F yesterday in a special Doctor Who Finale ident.
NG
noggin Founding member
Markymark posted:
noggin posted:
Markymark posted:

Yes ! It was the switching of the chroma sub-carrier p hase every a lternate l ine (hence the name !) that was the key. (Hue errors were converted into saturation increases (or decreases) which the human eye is far less sensitive to. Some Japanese TV manufacturers circumvented the need to pay AEG Telefunken the patent licence, by not having the one line (64 us) delay-line in the TV, and instead had an NTSC style hue control, for the manual correction of the hue (Thus negating the whole point of PAL !)


They still had the delay line - but used it to repeat the previous line's chroma didn't they - so avoiding phase alternation aspect of the patent? Effectively they created an-NTSC-like chroma signal by replacing the lines that were phase alternated by repeating the previous line so all the lines presented to the decoder were in the same phase, like NTSC.

If they'd just ditched the delay line they'd have had to have used Simple PAL - which would still require the patent?


Well now, having read up this morning on this Telefunkun did unsuccessfully try and sue Sony for what they called a PAL-S decoder, using as you say a delay line to repeat the last line of chroma

http://www.radiomuseum.org/forum/45_years_anniversary_of_walter_bruchs_pal_color_television.html

(Scroll down to almost the end, 'Sony's Special Way' )


Ah - so I was right about the way Sony used the delay line in a non-PAL-D manner, but I hadn't realised PAL-S wasn't patented.
BL
bluecortina
D.Page posted:
Markymark posted:
PAL was a German developed and patented system, but otherwise 9.5 out of 10


Yes, Telefunken were the guys. Worth noting, though, that much of the basis of PAL came from NTSC, so when you say "developed", important to make this clear, I think.


Not so fast Mr Bond, or Dr Bruch maybe. RCA were well aware of the advantages of alternating the phase of the subcarrier when they were developing the system that eventually became known as NTSC. I have a copy of their paper on it somewhere but it may take some time to try and dig it out. They dropped the idea at an early stage as they thought it would make domestic receivers too complicated (In the early 50's we're obviously talking of valve technology here).

So Bruch was sort of re-inventing a previous idea, and of course he did introduce Bruch blanking but there's some doubt that it was strictly necessary.
BL
bluecortina
noggin posted:
Markymark posted:
noggin posted:

They still had the delay line - but used it to repeat the previous line's chroma didn't they - so avoiding phase alternation aspect of the patent? Effectively they created an-NTSC-like chroma signal by replacing the lines that were phase alternated by repeating the previous line so all the lines presented to the decoder were in the same phase, like NTSC.

If they'd just ditched the delay line they'd have had to have used Simple PAL - which would still require the patent?


Well now, having read up this morning on this Telefunkun did unsuccessfully try and sue Sony for what they called a PAL-S decoder, using as you say a delay line to repeat the last line of chroma

http://www.radiomuseum.org/forum/45_years_anniversary_of_walter_bruchs_pal_color_television.html

(Scroll down to almost the end, 'Sony's Special Way' )


Ah - so I was right about the way Sony used the delay line in a non-PAL-D manner, but I hadn't realised PAL-S wasn't patented.


But you only get half the vertical colour resolution?

Newer posts