Yes, I do recall the Zenith SSAVI descrambler units, made for use with cable TV systems of the '70s or so to descramble, for a fee, pay-TV movie channels and such. (A subscription TV channel in Cleveland in the late '70s-'80s used a version of these descramblers to unscramble their STV services, called Preview; the service also made use of a special cut-to-channel TV antenna just for that station, channel 61.)
However, my point was that Zenith is in fact out of business as far as the manufacture of TVs is concerned. As I mentioned, their name and logo were still being used on television sets made by Goldstar as late as the late '90s and the first couple of years of the 21st century.
I remember reading about the Zenith Radio Corporation's first (and only, to the best of my knowledge) attempt at pay TV, known as Phonevision. (I knew someone in the '70s who had a 1954 Zenith console b&w TV with a Phonevision socket, but to the best of my knowledge the person, who lived in suburban Cleveland, never used it and may not have even been aware of Phonevision at that time.) This system may have worked well at the time (1950s), given the state of the art then, but in all honesty, today's pay TV services would almost literally run rings around Phonevision (if the latter were still in existence, which of course it isn't), since they can provide better pictures (in color, for one thing) and more features than could Zenith's system.
I was not aware, however, that Zenith's R&D division was responsible in large part for ATSC 3.0, the new DTV standard. In fact, I was not aware, until I read the posts following mine in which the statement was made that Zenith is still very much alive and well in the 21st century (albeit no longer as a television manufacturer), and that the company was instrumental in the creation of the new DTV standard. I looked at Zenith's website before starting to write this and was amazed at what the company is still up to in this century, after thinking for years that Zenith was dead, never to return.
Thanks so much for letting me know that Zenith, which for decades was my favorite make of TV and stereo gear, is still alive and well in 2017 (and I hope for many years to come), although not as a manufacturer of TV sets or other home-entertainment gear. I knew Zenith's TV manufacturing plant, now (late '90s-early 21st century) making Goldstar TVs under their own brand, was in trouble ("the handwriting was on the wall", so to speak) when I read about the company's last TVs, made in the late '90s-early 21st century, having problems with CRTs that shorted after one or two years, taking the set's entire video chain with them; I recall as well that these sets had HV regulation and other problems.
