Hi Stan,
I would suggest, instead of cutting pieces of coax to test different phases,
use a "Phaser":
https://www.k5ua.com/technical.htm
You can easily convert an antenna tuner into a "Antenna Phaser" and enjoy the
best out of your antennas.
73, Maximo EA1DDO
________________________________
De: TowerTalk <towertalk-bounces@contesting.com> en nombre de Stan Stockton
<wa5rtg@gmail.com>
Enviado: viernes, 15 de noviembre de 2024 22:38
Para: TowerTalk@contesting.com <TowerTalk@contesting.com>
Asunto: [TowerTalk] In phase?
A little dilemma - I just put up another tribander at ZF9CW on my new tower. I
originally had two smaller tribanders on a separate tower. I had built two
identical chokes and they have another torroid across the feedpoint that would
electrically ground both sides of all three driven elements to the boom for
additional top loading for my 160m shunt feed.
When I took the smaller antennas down I did a little work on the balun -
re-soldered some connections, etc. I don’t think I changed which side of the
element the center conductor would be attached to but cannot be 100% positive.
Now, I decided to make another large tribander and built a swing arm so I can
rotate it and have the other balun on it. I know I didn’t change that balun.
The antennas are at 78 and 47 feet. I am seeing some S Meter readings when
switching between, upper, lower, both that make me wonder whether I actually
have them 180 degrees out of phase instead of in phase.
I could add an electrical half wavelength of coax for one band and evaluate it
over time, with and without that extra coax in line with one antenna and try to
determine what I’ve got. Would it be good enough to call CQ on 15m, look at
the RBN for JA spots and then insert a half wavelength of coax for 15m and do
it again comparing the results and assume that in phase would be the better of
the two?
I don’t want to do what would be necessary to reach the balun on the top
antenna which is out about 8 feet. That choke across the feedpoint makes it
impossible for me to just use a piece of aluminum tubing as an extended lead
from an ohm meter to tell what is what. I could more easily tilt the lower one
up and get to the balun to change it if I knew for sure they were currently out
of phase.
What I’m looking for from the experts is the best way to determine whether
these antennas are in phase or out of phase without a lot of guesswork or info
on how I could best flip the phasing 180 degrees for all three bands. I would
not necessarily know which was which but have the ability to flip it 180
degrees from wherever it currently is.
Thanks…Stan, ZF9CW
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