What happens to power loss in a feed line?

What happens to power loss in a feed line?

What happens to power lost in a feed line? All cables, no matter how well designed, have some “loss”. Feed line, like other cables, also has resistance. This resistance results in power lost when going through the feedline and being converted into heat.

How does the length of a match transmission line affect the SWR?

Line length doesn’t matter when the line is properly terminated, the input impedance will remain unchanged with varying lengths of line. High SWR on a line with high matched-line loss will produce significant additional loss on the line.

When transmission line is terminated matched load then SWR will be?

The SWR is a measure of the depth of those standing waves and is, therefore, a measure of the matching of the load to the transmission line. A matched load would result in an SWR of 1:1 implying no reflected wave.

How much power loss is caused by SWR?

And note that the SWR at the load is 3.20:1, not at all extreme. Also interesting is that for this combination of load, transmission line, and frequency, at lengths below about 55 ft the total power loss is actually lessthan the “matched line” loss.

What are the losses in a feed system?

The feed system permits very efficient coupling of power in to the antenna itself, but the resistive and radiative losses are all quite low, requiring a spectacularly high circulating power to achieve equilibrium.

What should a SWR reading of 1.6 be?

Using an swr reading of 1.6 :1 in the example above, our percentage of reflected power would be 5 % with 95 % of transmitter power usable or 95 watts to the antenna assuming no other loses in your feed line or antenna.

Why does the SWR meter never see line loss?

It called line loss which increases the SWR AT THE ANTENNA and, the SWR meter will never see it! You will learn why in the links below. Here is a hint for your station SWR record keeping! When taking the final swr measurement on your new antenna system or after making changes to it, record them in a permanent record for safekeeping.