F-Connector 75 Ohm Terminator

These are 75 ohm terminators on a male F connector. They are designed to terminate unused cable TV or Off-Air TV signals on a coaxial cable. Not designed for satellite signals. These will short out DC signals such as IR and Remote Power signals that may be on the coax. (See DC blocking terminators.)

Terminators do two things. The first is that they cut down on electrical reflections from unterminated (and unused) feeds. These reflections from the unused ports can cause interference with the primary signals on the rest of the RF distribution system.

The second thing they do is to cut down on the emission of RF signals into the air. For antenna systems this really doesn't matter, since the signals are already in the air. But for cable (CATV) signals, the cable company goes to great lengths to keep their signals "inside the cable." Proper termination is an important part of this. The FCC investigates extreme interference problems.