Compatible colour TV

[DrZarkov]

As Andrews thread completely went under in a discussion about CD-rom, a second try, because I'm interested in colour-NBTV, too.

To the practicle side: you need kind of a "colour separator" after the pre-amplifier, I think. How does it works? Are there any circuits available?

[Steve Anderson]

As Andrews thread completely went under in a discussion about CD-rom, a second try.

To the practicle side: you need kind of a "colour separator" after the pre-amplifier, I think. How does it works? Are there any circuits available?

Yes, sorry. I do feel somewhat responsible for 'hijacking' the subject matter.

In the past colour separation for cameras was done with dichroic prisms and three seperate tubes for the R, G and B channels then matrixed and encoded into a composite signal (PAL /NTSC/SECAM). Nowadays colour separation is usually done within the CCD sensor itself, though there are still cameras around that use three separate CCDs.

In the receiver the signal was decoded back into RGB, each one to drive the appropriate gun in the CRT.

With NBTV we face the same dillema that was a challenge in the 40s and 50s, squeezing three signals into the same bandwidth that the monochome signal occupied whilst retaining compatability.

Klaas has done a lot of work on this, however his proposals are digital (nothing wrong with that). An analogue system for NBTV would not be easy and any form of sub-carrier (as used for 625/525) would probably be very visible on a monochome display.

Steve A.

Now about those CD-ROMs....

[DrZarkov]

For the beginning the digital NBTV-CD colour compatible system would be fine. To do it thr "right" (analogue) way I would suggest to concentrate on Steve's tricolour SDS-system as discribed earlier in this forum or in the new newsletter Vol. 32 No. 4.

[Steve Anderson]

To do it thr "right" (analogue) way I would suggest to concentrate on Steve's tricolour SDS-system as discribed earlier in this forum or in the new newsletter Vol. 32 No. 4.

Not having re-newed my subscription for a couple of years I don't have that issue of the newsletter. I also looked through the posts on this board and couldn't find the item referred to.

Perhaps you could point me in the right direction?

Steve A.

[DrZarkov]

Follow this link: http://www.taswegian.com/NBTV/images/SDS.pdf.

[Steve Anderson]

Follow this link:

Thanks for that, I'll digest it in the morning, I've had too many beers to take it in...it's 6pm Sunday here now...been out with the lads at the 'Jungle Bar' most of the afternoon...phew!!

Steve A.....(Burp!).