The first and foremost was was to know that when I used the center C31XR of
a 3-stack the signals would always go down noticeably. I don't climb - the
guy that was doing my tower work at the time was Justin (to give him
credit - unfortunately I don't remember his call or last name) ... I had him
ohm it out and it was readily apparent that top and bottom were the same -
the center different. Changed all out with Balun Design units and it worked
as expected.
Gary
[as for disparaging someone - my only comment was the units I had were
indeed junk. I'm not being hyperbolic here - the connectors turned in the
housing! And then there is the one that although clearly marked was not
wired correctly. The construction once in hand is obviously a poor man's
unit not expected to be used on high power (how much I'll leave for others
to say) nor where replaceability was potentially a serious problem]
-----Original Message-----
From: jimlux
Sent: Wednesday, March 15, 2017 1:41 PM
To: towertalk
Subject: [TowerTalk] checking balun phasing
On 3/15/17 9:06 AM, StellarCAT wrote:
the ones I had were junk. Two of the 5 fell apart on their own (bad
internal soldering) ... one was used in a phased array and even though
the markings were followed for getting the right phasing it was indeed
phased backwards forcing a tower climb and real stretch to get to that
one. I changed all that I could get to with a Balun Design balun and
never looked back.
Gary
K9RX
This prompts an interesting question. What would be an easy way to
check the polarity of an RF transformer (which is what the Balun sort of
is). For some designs (coax choke) you could measure DC continuity, but
there are designs with DC continuity, but where that wouldn't tell you
the phasing.
Assume one has a antenna analyzer of some sort (Yeah, if you have a VNA,
it's trivial).
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