Basically it shows problems in the plant
like bad cables, connectors, splitters, amps, ingress ect.. You also use it
to align the forward and return amps.. You are trying to maintain
unity gain in the plant.
There is a sweep transmitter in the headend that generates signals acrosss
the spectrum 50 up to 1Ghz. Those signals are seen in the field by the sweep
receiver and showing as a line(frequency response). At the node once you
set up a the tilt then output level you reference the node and your trying to
match the node response(which is a flat line). As you go through the system you
are trying to maintain a flat response to your last active in the plant.
Depending on the system, you will be given a spec to meet at the end of line
like 4dB peak to valley.
Now the same holds true for the return, but the sweep receiver generates
the carrier from 5-42mhz and the headend unit makes the readings and send that
info back to your sweep receiver. This is also displayed in as a flat line.
