The first Zenith solid state color chassis with varactor tuning?

[drh4683]

I am interested to find out if anyone here has what I believe to be the very first zenith solid state chassis color TV which also had varactor tuning. Perhaps some of you are familiar with the 40BC50 chassis, for 1971. There were apparently only three models available that year with this chassis. I have the service manual for the 40BC50 but for some reason it does not show a top view of the chassis, and a side view of the rear apron. All you get is a schmatic diagram. Normally, the other side of the fold out schematic is the actual top view of the chassis with component locations. For some reason, zenith manual CM-118 fails to show that information. I am lead to believe that the 40BC50 is very similar to the 1972 chassis, 25CC55 which is a little more common.

What I find interesting is that the 40BC50 as well as a select number of models using the 25CC55 used this unique looking varactor tuning system which I have a photo of out of a 1972 zenith brochure. The system was not mentioned in my 1971 consumer brochure, but it was listed in the 1971 showroom book which I have.

If you look closely at the photos of the tuner, it uses the motor drivin star wheel tuning stop system like the rest of the space command sets of the 60's-early 70's. The bottom of the control appears to be a meter which points to the various stations. The meter appears to be an electronic type? I dont see it being a mechanical channel indicator is it? I know many varactor tuners used a worm gear drivin mechanical indiator. Not sure, again, never seen one before.

The reason Im showing these pictures is to get an idea what a TV with this particular tuning set up looked like. This tuner apparenly was only available on the "highest" of the high end models, thus you only get to see the cabinet with the doors closed. Due to zeniths marketing technique by not showing another view of the TV with the doors open, I have no idea what the control panel and escutcheon looks like.

Whats also interesting, zenith didnt really make a big deal about this "new" varactor tuner in the brochures, it was just part of the lineup of optional tuners like the common "gold video gaurd" tuners and they just make a mention of it being a "new exciting concept in TV tuning".

The models shown are from the 1971 Zenith showroom catalog and using the 40BC50 chassis: B6786P, the "Newland" and the B6788DE, the "Ravenna". 1972 models look exactly like these ones but are models C6790P and C6792P respectively. Those ones must use the the 25CC55 chassis. For some reason I do not have any of those 1972 models in any of my service manuals.
Just as a note, the 25CC55 was available in a good number of models and available with conventional tuning methods.
Does anyone have any of these early varactor zenith TVs and can post pictures? Id really like to see one. I have the more common 25DC56 and 25DC58 varactor tuner horizontal solid state sets from '73. hopefully I can find one of these first generation models someday. We've all periodically discussed the RCA Transvista color, but I dont recall one of these sets ever being discussed with the 40BC50 (1971) which was introduced only a few years after the transvista (1968) and was 100% solid state right off the bat.

Anyone work on a 40BC50, was it a good reliable chassis?