Diplexer
UHF and VHF frequencies from different aerials can both be sent down the one cable by using a diplexer to combine the 2 signals. At the user end, another diplexer separates the 2 again.
- If one aerial is used to receive both UHF and VHF, only the user end diplexer will be present.
Its also possible to use a splitter to divide the signal instead of a diplexer, but this causes significant signal loss. Instead of dividing it up by frequency, a splitter passes some of all frequencies out to both outputs. Splitters work, but give inferior results to use of a diplexer.
A diplexer can't be used to divide a TV signal to 2 outputs for 2 TVs, it will simply send all the TV frequency signal to one output only.
A diplexer has 3 ports, and it matters which cable connects to which. No ports can be swapped around.
Triplexers combine or split 3 different frequency bands. In principle its possible to transmit medium wave, VHF, DAB, TV and satellite signals all on one feed cable.