Originally posted by: DeschutesCore
A cable trap is used to block certain frequencies and was widley used up till the 90's. Only a few areas use them now, Cox in the Warwick area of Rhode Island is one for example.
Multichannel negative filters (traps) block groups (or tiers) of channels from nonpaying subscribers. The trap filters out selected frequencies, utilizing a passband that allows (or passes) the frequencies (channels) purchased by the subscriber and a reject band that blocks the frequencies from subscribers who did not pay for them. By blocking groups of channels, there is no descrambling of signals, eliminating the need for expensive subscriber equipment. Instead, filters are installed outside the subscriber's home, either on the directional tap port at the pole or in a lockbox mounted on the side of the building.
Management of a customer's premium channels was a pain in the ass in those days. it also took a lot longer to activate new channels, etc. Plus, bad traps were constantly ignored in service calls. I'm glad they're almost gone.
There is also what is known as a terminator that is installed to block all signals, it is just like the 75 ohm loopback terminators uses to prevent signal leakage on amps. They use a security driver to ensure they can not be removed by hand just like traps, and they look identical in most cases, but traps are quite a bit more expensive and are labeled.
DC
