Consider this: A 17-meter full-wave loop, fed by 75-ohm coax threaded through a balun of several ferrite beads, produced a 4:1 SWR, and the rig could not drive full power into it. It needed a tuner of some sort. The SWR is just a clue: It doesn’t give enough data to do much. We need the S parameter, S11, of the coax. Why? Read on …
So what is an S parameter, and how many are there? They’re parameters of a network. Let’s demonstrate with a cable TV 1- to-4-way splitter that cable TV signals to four rooms of a house. It’s five type coax connectors () show why