TP-120 4-Conductor Telephone Plug 218BGPX The other ports J2-J4 is

The other ports J2-J4 is DC blocked and loaded with a 200Ω resistor to simulate antenna current draw which prevent alarm faults

This GPS amplifier accepts signals covering  all major GNSS constellations with excellent gain flatness and a very low noise figure

and can withstand the shock and vibration often present in hostile environments

no volume control

This loaded DC blocked passive splitter features one input and two outputs for splitting gps RF signals from 1

TP-120 4-Conductor Telephone Plug 218BGPX The other ports J2-J4 isThe TP 120 telephone plug is a four conductor plug with nickel plated, brass contacts molded into a plastic body.