RE: Kat5 Anomaly

["Keith Doxey" <ukha@xxxxxxxxxxx>]

Hi Mark

> Hey Keith,
>
> OK so I tried it on S-Video last night and it was slightly better. The
> blue screen anomaly vanished.
>
> My problem now is that I think I may stick to composite. If I use
> S-Video I loose the ability for scart switching which at the moment is
> an essential SWMBO component. If it's not done with one button press,
> she is not interested :D
>

Thats the one thing that REALLY bugs me about SCART. The original spec was
only for Composite/RGB and pin 16 was used to signal the change. Pin 8 was
originally used to indicate TV/External.

The spec was then ammended to include Widescreen capability which changed
Pin 8 from a 0/12v signal for TV/Ext to a trilevel signal 0/5/12v for
TV/16:9ext/4:3ext.

A further amendment was to use the Red and Sync(CompositeVideo) pins for
S-Video Chroma and Luma signals but they didnt include any way of
automatically signalling that an S-Video signal was present.

Support for S-Video via SCART varied depending on the manufacturer.

I have a 14" Bush TV that will support S-video via SCART but only by
pressing the AV button to cycle between  TV/AV/S-VHS. Under automatic SCRT
control it will only do Composite/RGB and RGB is only availaby via auto, it
cant be selected manually.

The Mitsubishi I used to have would allow Manual or Auto selection of RGB
on
AV1 and would allow manual selection of S-Video via AV2 although auto would
only ever give Composite.

I now have 2 JVC Tv's, one about 10 years old and the other one year old
and
both of these allow SCARTs to be configured as S-Video in which case
anything grabbing Pin8 will automatically be S-Video unless it also signals
RGB.

I just wish manufacturers would standardise on how stuff works particularly
thing like POWER buttons. Some of my TVs toggle the power, others are only
an OFF and you have to press a channel number to turn the set on.


> So considering that it's a composite connection is disconnecting pin
19
> from the scart still valid ?
>

Absolutely. If there is any crosstalk in the cable that will kill it stone
dead. Having said that, that is assuming that the cause of the picture
disturbance *IS* crosstalk. It could just be the artifacts that are always
there in a composite signal and the fact that you now have a higher quality
distribution is making them more visible.


> Either way, it's still a way load better than my old RF system :D So
far
> I am very impressed with the KAT5's. Great piece of kit.
>

Thanks :)