Base PCE S-video question.

[Eddiesamma]

So I have a tg16 I modded with a status light and s-video ect and wanted to swap to a pc engine for my first region mod ect ( I just love the foot print of this thing) I successfully region modded it with the twin multiplexers and a toggle switch added stereo with 2 100 uf caps at 16 volts and then went to the s-video mod. I have removed the resistor that combines the luma to chroma lines so I can bypass the pf filter cap (don't care to have composite) I used the same 3904 npn and 220 ohm resistor I used in the tg16 and I noticed right off that I have a checkerboard pattern in the color on my tv. I have a samsung lcd I play most of my consoles on if that helps, I went back to see if maybe I had some interference from an audio line coming through or something. I was wondering if anyone else has this problem or if it's something else. Just checked and it's nearly unnoticeable on a s-video crt.Also TG16 does not have this checkerboard pattern.

[pulstar]

Might be a silly question, but can you not just go the RGB route directly via a scart cable?

[Eddiesamma]

Not as of right now. I'm super happy with the tg16's S-video and even the pce's I'm just trying to find out if anyone else has this checkerboard pattern on their white base pc engine.

[Keith Courage]

I'm not familiar with the way you are trying to wire up your s-video. I've always done it this way. 

http://postimg.org/image/mlr5tkxzt/


As an alternative to getting composite off of the exp pin out on the rear composite signal can also be grabbed from one of the RF port pins. I believe it's the center of the three pins that go to the RF jack.

Ground should be tapped from either the exp pin out on the rear of the system or the HU6260 chip itself. Otherwise the picture will look somewhat blurry on a US Turbo grafx system.

[Eddiesamma]

Hey Keith, it's the same method using the rf's composite for my C signal I just omit the low pass filter cap by removing the resistor that combines the luma and chroma signals coming from the huc6260. I still build the npn transistor and resistor amp. I used a 3904npn and a 220 ohm resistor. Looks great on the tg16 but breaks composite out and with the pce it looks just as sharp and vibrant but it has a checkerboard pattern.

[Eddiesamma]

[Eddiesamma]

I hope that helps lol.

[Keith Courage]

i have seen the checkerboard pattern before but not as strong and only on blue backgrounds when games are scrolling.

maybe it has something to do with removing the resister on the board you mentioned?

[Eddiesamma]

The method I used for my consoles is on the s-video mod thread I think Drakken was the one who thought to remove the resistor but he was doing 2 direct taps for Y and C and TheSteve mentioned that the amp must still be built for that method. And my TG16 is modded identical to this and it looks perfect, no checkerboard pattern whatsoever. I may redo it and just double check that chroma and luma are completely separated. It almost seems like I could turn the sharpness down on my television and remove it.

[Eddiesamma]

Been a while but I found the problem to be where I was pulling composite from. Swapped from the expansion slot to the rf pad and viola perfect picture.