This is another bloody 1084sd-1 problem,which i assume to be caused by it getting a ntsc-j rgbs signal from my newly acquired ,official jap mega drive.
I am feeding the monitor r g b cvid gnd/Vss ,from my scart to db/e9 male plug .The scart plug is internally wired as so, r g b with a 75 ohm resistor in series on each line, cvid ,5Vcc going through a 100 ohm series resistor ,Vss and mono audio connected to both L & R scart pins .
Now when i feed the 1084 a pal I rgb signal from a uk master system,uk ps1 and 2 ,then i get a rock steady image ,but using the ntsc-j mega drive 1 ,gives me a tiny bit of wobble on the very top of the image,it bends to the right .I can fix this by using the horizontal control, to shift the image further to the right or left,but doing this causes dirty great big black borders down one of the sides of the image.So if i want a full screen image ,i can't ,only with a PAL I console connected will i get full screen perfection .
I do remember seeing something on this site regarding the lm1881 and not connecting something to ground with a 1084 ,as you would get a wobble ,but i'm not using a sync stripper ,so ?
My rgb scart cable is around 3 metres long ,just incase this could be effecting the video stability.