View Full Version : No interlacing is ocurring


lnx64
03-20-2012, 12:18 AM
For some reason, my TV in my sig, is not interlacing properly. It doesn't do this on the cable DVR box, but it IS doing it on VHS and my Roku 2 box.

What is happening is, the 2 fields are landing on top of each other, instead of being seperated. On the DVR box, it is a perfect interlace, each field is spacing as it should.

I thought perhaps the VCR and Roku box were malfunctioning, but on every other TV I tried, it looks fine.

EDIT: http://img.photobucket.com/albums/v395/Evilweredragon/IMG_0185.jpg
See in the picture the perfectly defined scanlines. If it was interlacing, it wouldn't appear as clear as that.

EDIT2: http://www.youtube.com/watch?v=it85qBh7IgE
In this video you can clearly see the scanlines sitting still. Once again though, this Roku box is interlacing fine on other TV's.

wa2ise
03-20-2012, 02:31 PM
VCRs don't always produce vertical timing that is accurate enough for some sets to interlace correctly. Broadcast TV stations always had precise timing of sync pulses, per FCC rules, and many TV sets expected perfect signals, as the only signals in their day were broadcast over the air TV channels. Later TV sets were designed to deal with sloppy timed signals better.

Electronic M
03-20-2012, 05:08 PM
It don't look all that bad to me....Of course I use one of these as a daily driver.
http://i1095.photobucket.com/albums/i469/ElectronicMemory/DSCN0432.jpg

lnx64
03-20-2012, 07:11 PM
VCRs don't always produce vertical timing that is accurate enough for some sets to interlace correctly. Broadcast TV stations always had precise timing of sync pulses, per FCC rules, and many TV sets expected perfect signals, as the only signals in their day were broadcast over the air TV channels. Later TV sets were designed to deal with sloppy timed signals better.
I guess even the Roku has bad timing.. Kinda surprised that these days they would still be sloppy. Even my Sega Genesis can properly interlace (on the few games that supported it).

miniman82
03-20-2012, 09:37 PM
Run your signals through a TBC, I believe that's the way to cure this.

ChrisW6ATV
03-20-2012, 10:28 PM
Could it also maybe be an AGC issue?

lnx64
03-23-2012, 12:06 AM
So based on what I was told on another thread for a different topic, I learned about line paring.

So I adjusted the vertical hold very slowly and viola! I got interlacing. BUT!! The fields are backwards, so everything looks like total crap.

On any other TV the fields are presented in the right order.

So now I wonder what could be causing this. Maybe it's the RF modulator.