Mystery set at a sale this weekend

[TUD1]

1976 Zenith System 3. Got it for The Best Price. When I showed interest in it, they pretty much begged me to take it.

[Jon A.]

Originally Posted by TUD1

1976 Zenith System 3. Got it for The Best Price. When I showed interest in it, they pretty much begged me to take it.

I'm thinking the manufacture date label is worn, I don't think the System 3s were out until 1978.

[zeno]

Originally Posted by Jon A.

I'm thinking the manufacture date label is worn, I don't think the System 3s were out until 1978.

System 3 "style" chassis came out the end of J line on a few
TOTL consoles. As far as I know System 3 was never used on
the sets or in literature.

K line brought the name & ad campaign. Sets were 19" & 25".
System 3 was a feature list not a chassis. J & K sets used the
9-153 HV module not the 9-160. They were the most reliable
sets Zenith ever built. Also the CRT's used a green phosphor
that was stunning. One thing I never tried that I would like
to is swap the 9-152 with a 9-152-02 that has a comb filter.

L line brought the 9-160, comb filter, 13" & 17" and RAT tuner.
Reliability dropped but sales went through the roof......

73 Zeno
LFOD !

[andy]

///

[old_tv_nut]

Originally Posted by zeno

... Also the CRT's used a green phosphor
that was stunning. ...

This is a very interesting observation.

I believe by this time they had dropped the cadmium from the green (which made it brighter, but yellower, producing a cyan color bar that was very grayish). (The cadmium was determined to be an environmental hazard.) This means that the green formula was based on copper-activated zinc sulfide like everyone else's green, but there could be unique differences among makers depending on the use of co-activators like gold or aluminum. With the deletion of cadmium, the efficacy of the green was reduced such that it could be the limiting primary for tube brightness rather than red, for D65 color temperature. However, no TV manufacturers at the time setup for D65; they were generally much more blue/cyan, partly as a habit from earlier days. Zenith used a unique 8000K setup that was not as blue as others, but still had a clean white look that accented reds and yellows by contrast, and provided more stable skin tones. I don't know exactly what combination of activators Zenith used in green or the exact color coordinates of the resulting green. I also note that the "stunning" nature of a particular color bar can be influenced greatly by the color demodulator gains and angles.