Tom wb6b is correct.
run voltmeter along the line to measure the peaks and minimums .
Also, just because you get 1:1 doesnt mean your antenna is efficient. proving this, take a field strength meter and go plot your minimal and maximum readings from it out in the field with various settings.You can have a 1:1 and have a signal that cant make it out of the county if your feed system and antenna is crappy.Or poorly set up or calculated wrong Also you can prove this by received reports on air , , Also the lower the noise level on receive when adjusting a match, means usually you are closer to a match for the radio.Meaning the received signal will be coming in louder and clearer. Just my own experience with my own equipment.
This is my experience with my own homebrewed equipment,.
73
David
ac9xh
