My feeling is that the feed-line to each radiator is part of the grounding.
You have 9 radiators. If you have 1/4 wavelength between each element you would
have about 3/4 wavelength between each element and the center. I assume you
have placed the combiner in the center. An open end wire (any type) is not that
bad of a grounding radial. The common mode choke is there to isolate the
feed-line from the combiner and that way act like an open end.
Hans - N2JFS
-----Original Message-----
From: Roger Parsons via TowerTalk <towertalk@contesting.com>
To: Tower and HF Antenna Construction Topics. <towertalk@contesting.com>
Sent: Thu, Sep 23, 2021 2:50 pm
Subject: [TowerTalk] YCCC 9 Circle Receive Array
I have recently completed building a YCCC 9 Circle array, and it seems to work
quite nicely. This replaces a receive 4 square using top loaded elements - I
could never get that to last as animals would break one or more of the top
loading wires mistuning the array.
The instructions for the YCCC array are explicit that there must be common mode
chokes between each element and the combiner unit. That is obviously a good
idea, but I can't understand why they suggest putting them at the combiner unit
end of the feed lines to each element, and my feeling is that they should be at
the element ends. (The elements have a very poor ground, and the feed lines are
significantly long. Surely that means that the high impedance of a common mode
choke at the combiner will be transformed to a different and probably lower
impedance at the element. The effect of that could be that the feed line
becomes the main and unpredictable ground for the element, and different for
each element, which I think is exactly what is not required.)
Comments would be appreciated.
73 Roger
VE3ZI
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