Video input mod and vertical poor interlacing

[Alex KL-1]

Originally Posted by zeno

With the resolution thing if you feed it composite to a set without a comb
filter your highs will get thrown away. With a comb filter you jump up
to 330 lines & improved other things. IIRC the most lines on
older sets was 450 lines on S-video etc IIRC.
Combs came out apx 1979 from Maggy. Others followed. Alwas on high end
19" & up.
Great to demo. On the combed set you see individual hairs, tiny
freckles & no more barber poling on checkers & lines. Easy step up
on the sales floor.

Interesting about the resolution. Last year I got a VGA to composite video converter for my brother, and I tested it on my homemade TDA9373 TV (it have almost 9MHz of video output bandwidth and >7MHz processor bandwidth). Since it don't have comb filter, is almost impossible to read the text letter fonts from PC workspace. For comparision, with S-Video (from same PC I used in interlace tests), fonts are suprisingly clear and clean, being possible to find videos on Internet I want to watch, see notifications, etc, for example.
And, the same composite video modulator plugged on a LCD TV (with a digital comb filter), is possible to read most of text fonts.

I become S-Video addicted in 2005, when I finished my 29" TDA9373 TV, and I enjoyed to play Playstation 2 in S-Video on it.

In my input TV mods with S-Video, I eliminate the sound trap and/or chroma trap (in case of color TV) in the luma circuits (or leave it behind the video input switch), and resolution become good.

For resolution in general, in modded TV's, most times I perceive better sharpness on B&W TV's, due to absence of phosphour divisions, simpler video circuits without delay lines and many stages etc (less sharp highs cutoff).