Re: TED colors

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Wed, 10 Jun 2020 13:36:54 +0200 Message-ID: <58e66116-3097-edd4-3f1d-f2ef214b2c4f_at_laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 6/9/20 11:36 PM, HÁRSFALVI Levente wrote:
> 
> There's also a small design flaw in all 264 series machines: there is a
> ferrite bead in series with the common ground point of the video out
> port, which (i.e. the common point that has non-negligible resistance
> above the 1-2MHz mark) causes crosstalk between the signals. (This is
> the main reason why the separate luma-chroma output image of these
> machines looks bad... there is so much crosstalk between luma and chroma
> that it introduces visible moire on the image). All in all... if you
> want to get rid of a disturbance factor, find and short the FB between
> the machine's and the socket's ground.

I'm going to fix this on my systems. Lets see if it helps. Easy enough 
to reverse.

But at least on the C16 there is another reason why the luma signal 
contains way too much Chroma. Take a look at the board and you'll notice 
the chroma and luma signal traces right next to each other for quite a 
bit. Cutting one of them on both ends and running a direct connection 
from TED to the modulator with an insulated wire helped quite a bit.

  Gerrit