Main > Monitor/Video Forum
How to use SCART for our hobby
Zebidee:
@paradroid
That little umsa VGA-Scart device is pretty cool, thanks for posting up the link. Quite impressive, although I note that the price does not include the 5v power supply, nor the VGA and male-male Scart cables. 29 euros is cheap enough to make it competitive and a real option to building one's own cable, but the add-ons make it less attractive. They could easily add 10-25 euros to the cost, depending upon where you get them.
I had a look at your link to that other Scart cable with the 1k ohm resistors on sync. that might actually be a solution to the vague problems I have with 100hz Loewe tv in my vertical cab. worth a try.
@lettuce if you bridge Scart 20 - 16 then you can bypass the 5v power altogether. trouble is, it only works for some tvs. it is quite easy to make this kind of cable so it is worth a try. I have several different types of vga-scart cables on hand to use when testing tvs.
@joe contra what is bc548b again?
--- Quote --- joe contra
Zebidee
you will need the 100ohm resistor on the wire going into SCART pin 16
It's in the diagram. :)
--- End quote ---
yeeeaaaah! That's why I put the "the" in there. Just confirming that one needs to keep that one, even if you get rid of the other resistors & transistor in the diagram (ironically, I was trying to avoid confusion).
--- Quote ---joe
make sure they are outputting on negative sync for both horz and vertical
I saw some cases where the card didn't give negative sync, and it didn't let change this option.
With my card there is no problem with that.
--- End quote ---
Yeah. Video cards for make are so cheap these days, so it is probably easiest to just buy a compatible ATI or other card. On the soft15khz thread there's is a link to a list of cards tested to be compatible with soft15khz, and this is a good place to start.
The nVIDIA cards have an option to adjust sync in the control panel software driver thingy. It has been a while since I have tried to use nVIDIA cards though.
When I used the powerstrip software, it always gave an option to adjust sync polarity regardless of the card.
That sync converter is pretty noice, but still a lot more trouble than twisting wires! I've managed to avoid sync converters for all of my cabs so far. Still, pretty good to be able to do it.
Zebidee:
I also noticed that the Arcadeforge site sells a soft15khz dongle to make high-end video cards compatible with soft15khz.
I wonder what it does exactly ... And what it might do to the sync signals. It may actually be a cheaper way to make a video card compatible with simpler VGA-Scart cables (and therefore avoid the need to solder up sync converting PCBs).
http://wp1114205.wp150.webpack.hosteurope.de/xtcmodified/index.php?cPath=10
lettuce:
--- Quote from: Paradroid on April 07, 2012, 08:48:36 pm ---Breaking news!
I think it might be time to retire from building VGA to SCART tables. Gonna be hard to top this awesome little device in terms of features and price:
For sale over at ArcadeForge: UMSA - Ultimate SCART Adapter
--- End quote ---
Great find my friend!, one thing that bugs the hell out of me though is it requires a external power supply. He could of drawn the power from pin 9 on the VGA side if the user was using an ATI card :-(
lettuce:
--- Quote from: Zebidee on April 07, 2012, 11:24:54 pm ---@paradroid
I had a look at your link to that other Scart cable with the 1k ohm resistors on sync. that might actually be a solution to the vague problems I have with 100hz Loewe tv in my vertical cab. worth a try.
--- End quote ---
So rather that soldering a 1k resistor on to each of the sync wires, could you just solder 1 2k resistor to pin 20 of the Scart and solder the 2 sync wires to the other end of the 2k resistor?
apfelanni:
taking the voltage of pin 9 has several disadvantages. u need a card delivering 5 volt , a fully wired cable and after all u dont have 12 volt for correct av switch. so it features an external power supply or molex if u prefer taking 5-12 volt from ur pc .
im currently runnig a first test sample in my ok baby cab with the 25 inch sony tv . the auto power on tv-pc works great . guess i ll replace the second selfbuild cable in the other philips ok baby in the future . i kept the jpac for keyboard encoding , video and audio are running through the umsa device to the scart in of the tv chassis .
ps. chinese power supply , vga and scart cable is what usually everyone has laying around somewhere. u may combine vga and scart cable fitting to ur purpose , i took a 50 cm vga and a 1 m scart for example and kept the cables as short as possible. the idea was to leave it to the customer to pick cable length and quality he prefers. a chinese external power supply may cost 3 dollar and can be found anywhere.