SCART/RGB Questions

[ShutokouBattle]

I have some general questions about SCART and RGB formats. Someone told me that RGB over SCART does not require a ground. Is that true? In other words, if I connect an RGB-outputting device to a monitor, I only need one wire for each color, plus sync? And does sync need a ground? If you don't need to ground the R, G, or B leads why does SCART have pins for them?

Also, I was looking at a Sony PVM on eBay. I believe it was a PVM-20M2MDU. On the back there are BNC connectors for R, G, and B leads, and then a connector marked "EXT SYNC." Is that what I would connect the composite sync from a SCART cable to?

[neorichieb1971]

The whole outside of the connector is a ground.

Whoever told you that is talking out of his ***.

[Fudoh]

Is that what I would connect the composite sync from a SCART cable to?

only if the system in question uses pure sync already, otherwise you have to put a sync stripper inbetween.

You will also need ground on all of the connections. Not neccessarily inside the Scart connector, but every BNC line has Gnd on the outside connector and they should be connected to something on the scart end. It's usually safe to solder all the grounds together and connect them to Pin 17 (Video/Sync GND).

[fagin]

The whole outside of the connector is a ground.

Whoever told you that is talking out of his ***.

The outside is PIN21 and not all SCART configurations will use this ground.

The fact of the matter is, is that you don't need a GROUND on R,G & B for SCART RGB to work. The statement the OP was told is correct in that respect.

[ShutokouBattle]

Is that what I would connect the composite sync from a SCART cable to?

only if the system in question uses pure sync already, otherwise you have to put a sync stripper inbetween.

Wow, that sucks... my current PVM (13") has no problem with any of the systems I've connected to it. Do most systems output composite sync or what? Does it vary? How about SNES, Mega Drive, Saturn, N64 (a modded one), JAMMA?

Do they make cheap sync strippers?

[Fudoh]

The displays' specs vary. On the PVMs I had (ranging from 7" to 29") only pure sync was accepted and there was not picture at all when using composite video. (NTSC-) SNES, MD, Saturn and Jamma output pure sync as long as the cable is configured this way. No idea about N64.

You can easily test this: if you connect the sync line from the Scart cable to the composite video input of the monitor and you get a picture, then you're using composite video, if not, then you're using sync.

Do they make cheap sync strippers?

make one yourself...

[ShutokouBattle]

Okay, so I can connect the ground for R, G, and B leads to pin 15. Do I need to ground the sync lead as well? If so, which pin - I'm assuming pin 15 as well, right? Does the Dreamcast output pure sync as well?

Here's kind of a stupid question: so I need to build a new cable if I'm going to get a new Sony PVM. Obviously it'll need 4 BNC connectors and some kind of sound output (probably 2xRCA) on one end, and a SCART connector on the other end. What I'm wondering is this: should I make the SCART connector male or female?

As far as how I'm going to use it, at first it'll probably be connected directly to a SCART lead coming out of a console. For that situation it would be ideal to use a female adapter. However, I eventually plan on using a SCART switch so I don't manually have to switch the wires every time I want to use a different device. I've been looking at these a bit, and it seems they come in models that either have a male cable coming out of the device or a female port on the device itself.

So as far as I can see it would be best to make it a female adapter, because then it works in either situation. But perhaps there's a situation I'm not thinking of right now, so maybe someone can enlighten me.

Another similar question: does it matter much how long I make it, as far as retaining as much image quality as possible?

[fagin]

You can use the same source ground point for every ground going to your PVM. PIN 15 would suffice.

The Dreamcast will do both composite sync and video as far as I know.

For a conversion interface I would recommend using a Console SCART (RGB) Lead and then building a breakout cable. Use a SCART Female to Female "linking" block which plugs in to your SCART connector. You can then make or buy a Male SCART to RGBs BNC breakout cable with Stereo Phono's... all sorted. Very easy to sort.

Obviously being as it's an analogue signal length will play a factor.... I've never had a problem though.

[ShutokouBattle]

Well I have a female to female connector, but why not just build the female connector into the cable? It's easy enough to hack one of those connectors open and solder stuff directly to it.

Also, just for laziness sake I might want to buy one, but I can't seem to find one that fits the specs I need - SCART to 4xBNC and 2xRCA. Know anywhere I could get one like that? There's a breakout box on eBay, but it's way too expensive (considering I could make one for a fraction of that price), and plus it has female BNC connectors instead of male ones.

[fagin]

Yes... you can butcher the scart connector to female. My suggestion at least ensures you have an original SCART Lead for each console should you want to do something else..... like get an XRGB or something. Entirely down to you.

Put "SCART to BNC" in to eBay..... there's hundreds of them!

[ShutokouBattle]

What? How would making a female SCART to BNC adapter even affect the male console leads at all? You wouldn't need to do anything with them at all, as far as I can see. Maybe you misunderstand me, or maybe I misunderstand you.

To clarify, my idea: female SCART connector leading to 4 male BNC connectors and 2 male RCA connectors. You would then connect a standard, unmodified male console SCART connector to the female SCART connector, or go through a switch. Either way, the console lead is intact. Am I missing something here?

As far as searching for "SCART to BNC," I see about 5 results when I search for that on the American eBay page. I get about 14 results on the eBay.co.uk page. None of them are what I need.

[fagin]

What? How would making a female SCART to BNC adapter even affect the male console leads at all? You wouldn't need to do anything with them at all, as far as I can see. Maybe you misunderstand me, or maybe I misunderstand you.

To clarify, my idea: female SCART connector leading to 4 male BNC connectors and 2 male RCA connectors. You would then connect a standard, unmodified male console SCART connector to the female SCART connector, or go through a switch. Either way, the console lead is intact. Am I missing something here?

As far as searching for "SCART to BNC," I see about 5 results when I search for that on the American eBay page. I get about 14 results on the eBay.co.uk page. None of them are what I need.

OK.. crossed wires.

Agree with what you have said, with regards to "the" solution.

Regarding the SCART to BNC lead.... apologies as I assumed the leads listed were wired correctly. Some maybe, but it's not clear from the descriptions to be honest. The other route is to go for SCART to Phono and then use BNC adapters for the four phono's.

This is a very easy lead to make-up yourself and I would be inclined to do that tbh.

BUT........

You could even use this type of lead for 99p http://cgi.ebay.co.uk/New-Quality-Scart ... 33678259b2 and then resolder the connections in the SCART end to the appropriate required and then buy four "Phono to BNC" adapters, which cost about £1 each. I suspect the same things are available via the US eBay listings. Then use your Female to Female connector to join your console lead to this new one.

[ShutokouBattle]

So, I built this cable for my Sony PVM-20M2MDU. It works great, except I have this Super Famicom cable that isn't wired properly. The video's fine, but there's no grounding for the audio. I was dealing with this problem in a slightly different context before, and someone told me to use pin 17 for audio ground. I'm not sure if that'd be a good idea, since all of the video leads (R/G/B and Sync) are already connected to pin 17. What do you guys think?

To clarify, I'm talking about modifying the SFC cable, not the SCART to RCA (used RCA instead of BNC) adapter I have. The adapter I built is wired correctly, so I don't want to change it.

[fagin]

Ground is Ground on SCART so do it.