Quote:
Originally Posted by jstout66
I know this answer isn't very technical, but this is what my Uncle always said. (he had a Zenith sales /repair shop form about 1973-2000) Anyway.. when VCR's first came out (and they were a HUGE investment, if one can imagine today) the customers almost always bought a new set. Why? Well.. altho their old set might be functioning perfectly well off antenna, or cable, they were NEVER designed with the thought of home video. So this is especially true of tube sets, and even early solid state ones. You always got that "tearing". Funny thing is.. some sets might be fine, but most weren't. Altho your Zenith B&W is mid to late 70's, I suspect Zenith didn't put much thought into if a VCR would work on it. At that time VCR's were still fairly expensive, and most people would have never thought of using a VCR on a B&W set. Anyway.. he always said that if the set was pre-VCR, or not sesingned with the use of one in mind, the manufacturer cheapened out on the sweep circuits, which made for lousy VCR watching.
|
NOT due to "cheaping out" the circuits. Pre-VCR sets depended on the sync timing being correct, because they could then reduce the bandwidth of the horizontal AFC and therefore sync perfectly even in extremely weak/noisy conditions. VCR's came along with up to 1/2 line (!) offset of H sync at the head switching point, causing the "flag waving" effect; and manufacturers including Zenith had to compromise their over-the-air fringe reception by speeding up the horizontal AFC circuit so that the bend would occur in a few lines before the visible top of the picture. Sets ever after had more horizontal jitter in noisy conditions.