[QuadList] RCA Hetrodyne Process and Early Color

[Dave Sieg]

I nursed a TRT-1C back to health from the dumpster, and my recollection of
the color rack was a 5 1/4" rackmount set of modules, one of which was a
delay line with varicap diodes.  I understood that they derived an error
jitter signal and used the inverse of that to vary the delay so that the
output signal came out timebase corrected.  At least to within a cycle of
3.58.

I was following your description up until the "guess what".
Maybe I've gotten dense in my, ahem, advanced years.
How does mixing the two 19.8 MHz signals fix anything?
And what happens then, its divided back down to 3.58?
There must be some step(s) missing here...
(Or a few of my brain-cells! :)

Your description:

> First the video is sent through a low pass filter to remove the chroma.
> There is another path that is a high pass filter to provide chroma only.
> The Chroma is mixed with the reference 19.8 MHZ signal.  Buffered and then
> mixed with the tape 19.8 MHz signal.  And guess what, we now have stable
> chroma.  The chroma is now added back to the mono signal and we have full
> color.  BUT it is no longer true NTSC because the 3.58 and the H sync are
> not locked.
>
> --
Dave Sieg
http://www.zfx.com
http://www.davesieg.com
http://www.scanimate.net
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