how does the cable company filter channels?

Question

My connection goes from the street main cable to my TV. No cable box or anything else.
How does the cable Co. filter premium channels?
I had HBO and I canceled it and it stopped. How do they do that?

Answer 1

For blocking an analog signal they put a notch filter at the pole where your drop line attaches.

The notch filters out one or more channels depending on the filter selected.



Notch filters that remove entire channels are called 'Negative' Filters. Notch filters that remove sideband carriers to make a channel viewable are called 'Positive' Filters. Thus we have two different scrambling methods.



SEE: http://www.dewtronics.com/tutorials/descramblers/notchfilter/notch.html

Answer 2

Cable Tv Filters

Answer 3

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The cable line does have filters installed on them. The filters could be at the street side of your connection or outside of your home. Or they could filter the signal right from the cable box on your TV. All the filter is really doing is filtering a certain frequency from what is being allowed through.

Answer 4

I guess you didn't like the answers you got the first time you asked about this. I referred back to your previous question and saw your edit (https://answersrip.com/question/index?qid=20100222175301AAHFTkf&show=7#profile-info-f076mwF9aa).



I can assure you that if you have analog ONLY cable service, and if you are not receiving ALL of the ANALOG channels, there IS a trap. Once again, they are known as "notch filters" or "band-stop filters". That is the ONLY way that cable companies can block analog channels. You may not have seen it, or recognized it for what it is, but it is there. They look like this: http://www.amazon.com/Channel-Plus-NF-470-Notch-Filter/dp/B001VV0BFQ/ref=pd_cp_e_2



Almost all cable companies took HBO off the analog lineup years ago. Putting premium channels like HBO and Showtime on the digital lineup eliminated the need for all of the different filters that were required during the analog-only era, along with all of the problems that came with them- truck rolls to install/remove them, traps going bad, insufficient space in the pedestal, bad jumpers between tap and trap, and easy theft of service. To be frank, I'd be surprised if TWC still offers analog HBO.

Answer 5

The cable they use carries many Chanel's ,each one fed in from its own source.All they have to do is switch it off,a nd your tuner can not find it then.