[drh4683]

I've been trying to solve the 40BC50 mystery for quite some time and with no success. The factory Zenith service manuals gives schematic, but does not provide a top view of the chassis or any of the additional chassis details as they do for the other more common chassis. I have a '71 Zenith brochure, there are two models that supposedly have a 40BC50 chassis, but they are high end cabinets and they only show the set with the doors closed. So who knows what the control panels really look like. The 40BC50 chassis also used an electronic tuner. It was a motor driven varactor type, but it looked very similar to the turret tuners and also had a rotating drum channel indicator. It was a totally different set up compared to the vertical channel strip motor drive varactors used on the later flat chassis sets that we are familar with. They picture this electronic tuner outside of the cabinet in the brochure, but theres no picture of the chassis in the brochure.

I'll have to post the '71 catalog later on.