Main > Monitor/Video Forum
How to use SCART for our hobby
Zebidee:
--- Quote from: Rigby on June 12, 2013, 01:10:40 pm ---well, PC VGA ports typically only output 1V of signal, some monitors like 5V and don't amplify it themselves. I don't know what voltage SCART expects, but given that it's not a protocol or signalling standard, it seems that it would depend on the TV you're hooking up to. Amp it up to 5V and I think you'll have an amazing picture.
--- End quote ---
Rigby, while what you say about arcade monitors requiring higher voltage on RGB is true, the RGB TTL standard for TVs is only 1v. Should be no need to amplify the signal from a video card to a TV. I've done VGA/SCART to literally dozens of TVs and never seen an exception to this.
If one does need a video amp, Ultimarc sell the at reasonable prices. But it is likely not necessary. Better to check with another TV and another video input source first.
You could use a multimeter to check the voltage on the RGB signals but this is tricky as is must be done while the system is operating and requires access to exposed RGB signal wires while everything is turned on, in-circuit and working. I did this before with a JPAC from Ultimarc (which has an on-board video amp) hooked up to a TV and was surprised to find only 2-3v on RGB. In this case I has the opposite problem - the voltage was too high for the TTL TV standard 1v and the picture was "blooming" as the colours were too bright.
So I suggest testing the RGB voltage levels while everything is in circuit and turned on. Be aware that the RGB voltages will vary depending upon what is happening with the video signal, but should peak at around 1v.
arcadeswede:
Ok! No problem, I can check that with a multimeter. In my case, I should have a low voltage value, right? Under 1V maybe?
That's may be the reason why my colors are weak.
If the RGB signals ends up being at 1V I don't know what to do next.
FYI: I have a 12V source connected to the SCART plug to make my CRT TV select the SCART input when turned on.
Is this something I could use for amping the RGB signals if they're low?
I also don't have any resistors och anything in my SCART plug. Only wires connected to pins. Good or bad? Is there any resistors you really should have that I've missed?
NightSprinter:
Bit of a curiosity: I know there were some RCA Dimensia sets that had an "EIA MULTIPORT" socket, and earlier revisions only supported TTL signals. What about the port on later models that also had an s-video socket? I am curious about what type of RGB (if at all) was supported by the later CTC140 chassis.
Locke141:
Figured out I can buy SCART CRT TV's her in Tanzania for around $40 US for a 19 inch, with out haggling. As an American this is a rare opportunity. As a plus, we get a shipment back to the US when we move home as part of my wife benefits.
I'm tempted to pick up a larger TV as well as it is unlikely I'll have the opportunity to buy a SCART TV once I'm back in the states. Now my questions is what should I be aware of when buying one?
Paradroid:
--- Quote from: Locke141 on June 15, 2015, 04:37:07 pm ---Now my questions is what should I be aware of when buying one?
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Nothing in particular. As long as the TV supports RGB input via SCART (I have seen some that only accept S-Video via SCART) and also NTSC and PAL (I have only seen one PAL only SCART TV out of the 100+ I have come across in my travels) so you've got the 50 to 60 Hz range covered.
I guess the other consideration is whether you want picture adjustments via a Service Menu or internal trimpots. Both have their pros and cons.
Tanzania... I never knew they had SCART there! My 3 months in Berlin where heaven for SCART hunting but I didn't have enough money left to ship any back home... :(
Good luck!
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