[sci.electronics] Descramble using filter

yhu@umbc5.umbc.edu (Mr. Ying Hu; CMSC (GRAD)) (07/20/90)

Some cable companies use filter to descramble the video signal and you
can also get these filters from some mail-order dealers. I saw one ad
from a mail-order dealer that they sale these filters for channel 2 and
channel 3 only. Since you know all the VCRs have output channels to
3 or 4, I don't understand how come they use channel 2 or 3. Is there a
catch in it? Or channel 2 means the cable starts at channel 2?