No, in 95%+ of the situations, it will not be necessary to use the power inserter since the amplifier is usually mounted near a power outlet. There are no performance advantages to using the power inserter – it is only used to allow the unit to be remotely powered when the amp can’t be located near a power outlet. A power inserter is used to back feed power to the amplifier through one of the RF output ports. This allows the amplifier to be mounted at a location where power is not available. The output port that is used to back feed power is usually marked as RF Out/DC In or something similar.
It is important that if the power inserter is used that it is installed correctly. The PCTMPI1G power inserter has markings on the label to show the correct way to connect the cables. The side marked “To Amp” should never be connected to the TV. This port will have 12VDC on it, and it is possible that older TVs can be damaged by that voltage. Newer TVs should be protected, but not all may be protected.