Ghosting on RGB 7800

[centaur2]

Hello everyone,

 

last summer I bought a SCART 7800 including the Peritel cable from France.

 

The console does not deliver the kind of picture quality I am used to from other

RGB enabled consoles like the Mega Drive etc.

 

I have a lot of ghosting, both in 7800 and 2600 mode.

 

Is the 7800 not capable of crystal clear picture quality or s there any way to

improve the picture quality? I have already added some 220nF capacitors

to the RGB pins and a 75 Ohm resistor to Sync, but this didn't change much.

 

Thanks a lot

Sebasian

[centaur2]

Hi again,

 

I made some pictures.

 

 

 

 

Maybe ghosting is the wrong word, looks more like color bleeding.

 

Thanks

Sebastian

[Phredreeke]

I think it's because the 7800 generates Y/C internally, and converts it to RGB in a separate chip.

[centaur2]

Thanks for your reply!

 

Is there any way to improve the Y/C signal before it is converted to RGB?

 

Are there any mods out there that provide a better picture than the one I

already have?

 

Cheers

Sebastian

Edited February 5, 2011 by centaur2

[mimo]

use a Wii

[centaur2]

Why should I use an emulator when I have the real thing at home? I am just looking to get the maximum picture quality I can get

out of this machine.

[mimo]

sorry for my silly reply.

I get that blue ghosting too, although a lot of it can be reduced by altering the settings on the TV.

There are also 3 trim pots inside the 7800 that can be adjusted. I think the lower one on the piggy back board will reduce the blue.

Be careful though, the trim pots are fairly fragile and most have been hot glued.

[Atari_Falcon]

I have the same effect with my scart machine, too... maybe will change to a video mod...

[centaur2]

Thanks for the replies. I will try the trim pots.

Good to know that this is not only a problem of my machine.

 

I will give feedback after adjusting the trim pots.

[mimo]

Thanks for the replies. I will try the trim pots.

Good to know that this is not only a problem of my machine.

 

I will give feedback after adjusting the trim pots.

Make sure you mark the original position of the pots. and just to add, a small movement can make a big difference

[centaur2]

Too bad, I just tried adjustig the 2 trim pots, but they don't have any effect on the colours.

[mimo]

Too bad, I just tried adjustig the 2 trim pots, but they don't have any effect on the colours.

 

there are 3, did you try the one on the piggy back board?

[centaur2]

Too bad, I just tried adjustig the 2 trim pots, but they don't have any effect on the colours.

 

there are 3, did you try the one on the piggy back board?

 

Sadly, the 3rd trim didn't make any difference. It was not on the

piggy back board, but above it on the mainboard.