Where can I tap a sync signal for s-video?

[Keith Courage]

I mounted it directly next to the din5 port on the rear. I am not at home right now to be able to take a pic but here is an older pic of my system. RED is where I mounted the S-video jack. It makes it real easy having it there cause you can tap composite and the 5V right from the Din 5 port. I actually mounted mine right to the plastic with some glue and one screw for the hole in my s-video jack. I didn't actually solder it to the board. However, in the future I might consider soldering the grounds to the board since that spot on the board has a large area of ground to scrape free. It's almost like the system was setup for that spot to take an S-video jack in the first place cause it is the perfect size.  Alternatively you could use a Din 8 connector instead of a din 5(standard DUOs already have them) and wire it up to the other non used pins much like an RGB mod. Then make yourself a Din 8 AV cable with S-Video and AV on it. This method would take much more time not to mention the need for always having to have your specially made AV cable to use it. 

[thesteve]

there's mine
right next to my RGsB

[lastcallhall]

Awesome, thanks for the suggestions!

[Keith Courage]

The S-video I have looked good but was way to bright compared to the original composite. Meaning the colors don't look as good in my opinion being so bright. Since I had already bought myself a 5 pack of resistors I wired up a 2nd 100ohm resistor in series with the first one and it fixed it. The video looks awesome now. So I suppose if anyone else is thinking about doing this you might want to consider using a 200ohm resister instead of 75 or 100. Oh and here are some updated pics of where I mounted it. Because of where I mounted the jack I had to break off one mounting pole from the case lid. The mounted pole isn't an important one since no screws go inside of it and nothing goes around it. So if you don't have an 8pdt switch in your system then it might be better to put the S-video jack on the other side so you won't have to do any case modifying.

[thesteve]

as i said your resistance will vary depending on the transistor used

[lastcallhall]

as i said your resistance will vary depending on the transistor used

Yep, I had also wanted to test the signal with 220 or 330 ohms to see the difference. Thanks to Keith Courage for testing out the 200 ohm range. Still, I may get a variable resistor to play with the color a bit without having to destroy the circuit every time.

[Keith Courage]

I was wondering if anyone else has experienced this and if maybe there is a solution. On some TVs I notices wavy lines going across the screen with my S-video. It looks like what happens when you have ground interference. Could I maybe have a bad ground inside the system? I tapped my ground right off of the bottom metal plate. Is it maybe a bad s-video cable? 

[ApolloBoy]

I was wondering if anyone else has experienced this and if maybe there is a solution. On some TVs I notices wavy lines going across the screen with my S-video. It looks like what happens when you have ground interference. Could I maybe have a bad ground inside the system? I tapped my ground right off of the bottom metal plate. Is it maybe a bad s-video cable? 

Try moving your ground to a ground point on the motherboard itself and if that doesn't work, try a different cable.

[thesteve]

you need to tap your ground from the board, not the plate.
you could have a bad cable as well, but because this method uses a current controlled sig, not voltage controlled it should be less suseptable to cable issues causing noise (open cable= no pic)

[Keith Courage]

Well, I soldered the ground to the board itself and the issue got better but was still slightly noticeable. The rest of the problem got cleared up when I moved my S-video cable away from the other cables that sit behind my TV. My cable must have been getting interference from something back there. Thanks guys

[Keith Courage]

Well, after all the work messing around with the ground in my DUO and cables on my TV it turns out that the problem is my TV. I just remembered that I used to have issues with vertical lines when I used a DVD player on it before with S-Video. To test this out I grabbed my old 27 inch Toshiba out of my closet and hooked it up. Dam does the S-Video look good and no lines whatsoever. I think I might end up trying to find myself a different CRT TV cause my 36" Sony Trinitron just doesn't do S-Video without showing verical lines. Thanks for the help though. This is a killer mod with the right TV.

[ApolloBoy]

I'm in the process of trying this mod on a white PCE I got from Samurai Ghost, I'll let you guys know how it goes!

[Keith Courage]

I was actually surprised how easy it is once I got used to it. I was making it way more difficult in my head until you guys helped me out.  Really the difficult part is just trying to figure where or how to mount the S-video jack itself. On a pc engine you would be best using the kind you can solder to the board since you can remove the RF and have a nice big space of ground to mount to. With my DUO-R I went with a plastic style jack that screws into the casing as opposed to one that you solder to the board. I added some glue to the jack to make sure mine was solid cause one screw is hardly enough to hold the pressure of pushing the cable in.

[thesteve]

ive done 1 with the jack having a metal box (like the controller port) and i soldered it to the RF shield (the one pictured above)
the next had no shell, so i braced it and glued it to the housing

[ApolloBoy]

That's exactly the technique I used, I just removed the RF modulator and in its place soldered on a PCB mount S-video jack. I also put in some audio jacks, one on each side of the expansion port. I also used a 220 ohm resistor since I originally wanted to try a 200 ohm like Keith but only had 220s laying around. The colors are a tad bit washed out, but I think that might be because I'm more used to RGB these days.

But overall I'm pretty pleased with the result and now I have a PCE I can tote around to meetups and stuff with my friends!