eyewitness info birth of cable tv

[DavGoodlin]

Originally Posted by WA3WLJ

Growing up we had Super TV :


Super TV expanded into the Baltimore area in July 1982 on channel 54 WNUV. Unlike other pay TV channels, Super TV only broadcast from 7:00 pm to 1:00 am Monday-Friday and 3:00 pm to 1:00 am weekends throughout its entire run and never went 24-hour.
Subscribers received a 12 inch by 12 inch brown decoder box and a dedicated UHF antenna which was installed on the roof or on a balcony and aimed at the station's transmitter. When attached to a television, the box would filter in the Super TV movie channel. In the evening, subscribers could view a host of movies that were scheduled to play at that time.

Philadelphia had this on WGBS 57 in the mid 80s. The supplied antenna was a 24" boom/single-channel yagi OK for the metro area but not out the 50 miles via wooded hills. Super TV expanded local coverage by also using WTVE-51, an independent channel started in Reading 1980, allowing that little antenna to work locally.

IIRC, there was a 15 khz sinewave added to the video, synchronized to invert the sync pulse as Mr Squirrel says.
Also thanks for the missing piece of this puzzle by pointing out this early application of MTS, jogging my memory.
In order to de-scramble, you had to "extract" this pulse from the sound subcarrier, invert it and add it back to the video.
The decoder box looked very homebrew IIRC