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G0TEZ > HDTV 15.10.11 11:17l 62 Lines 2800 Bytes #999 (0) @ WW
BID : B40053G0TEZ
Read: GUEST
Subj: Re: Re: G0TEZ > TV standards
Path: IZ3LSV<F6BVP<F8COJ<VE3UIL<GB7YEW<GB7CIP
Sent: 111015/0148Z @:GB7CIP.#32.GBR.EU #:15046 [Caterham] $:B40053G0TEZ
From: G0TEZ@GB7CIP.#32.GBR.EU
To : HDTV@WW
I stand corrected Warren.
I have put the old book away but the +4.5 MHz FM subcarrier sounds right.
The Aussies use PAL with +5.5 MHz sound where we use PAL with +6MHz sound.
I didn't bother looking for the FM Stereo frequencies.
Yes, we abbreviated our colour ref osc frequency to 4.43 M c/s but it was
a lot longer, different to the US frquency because of the line scan. Our
Line osc freq was 15.625 KHz, easy to remember because we use 625 lines.
I don't remember the US one, just that it is lower because of 525 lines.
The burst was mainly used to invert alternae lines of R-Y to overcome hue
variations due to varying signal paths Phase Alternating Line (PAL) as
well as used in a comparator cct to lock the colour osc.
Much the same in SECAM ecept the burst switches alternate lines into a one
line store which is then combined with the next received line to remove
hue variations. The fact that each line is shown twice, hence Sequential
et Memoire (SECAM) helps reduce noise. That plus the fact that SECAM is FM
rather than PM made it the worlds most popular system until the advent of
digi TV where whole fields are stored.
As for DVDs I have hacked a few after looking at the .IFO and .BUP files.
All very complicated as you say but, if someone else wants to do the work
and I can get it for free, I don't care.
As for not being very good. The US tried the Field Sequential System with
it's spinning disk ( invented by JLB) then scrapped it in favour of the
RCA Dot Sequential System which wasn't compatible with B&W which they also
scrapped. When the National Television Systems Advisory Committee, NTSC
came up with a compatible system which worked, they couldn't risk
scrapping yet another. This was all in the early 50s when everyone else
stuck with B&W. It wasn't until 1962 that the exhibition in Belgium
displayed all three colour systems that countries decided which to adopt.
Pal is just an over complicated version of NTSC invented by Herr bruch at
Telefunken. The French did not like the Germans so Henri de France came up
with the simpler very different SECAM.
In the end 33 countries adopted SECAM, 13 PAL and 7 NTSC. It wasn't until
1967 that we finally adopted PAL. I had studied all three systems over the
years and would have liked to see SECAM just from a technical viewpoint
but
it wasn't to be...
Nuff said. I now watch a 42in screen with a 16:9 aspect ratio and stereo
sound which could be surround sound if I gave a damn and the TV cost an
equivalent amount of money to the 26 in colour in 1967, the 17 in 3 ch B&W
in 1959 and the 9 in 1ch B&W in 1949. If one thing does get cheaper it is
electronics.
73 - Ian, G0TEZ @ GB7CIP
Message timed: 02:47 on 2011-Oct-15 BST
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