[TowerTalk] Vertical Antenna Question

Rob Atkinson ranchorobbo at gmail.com
Thu Apr 9 15:45:32 EDT 2020


>I've been a broadcast engineer for 40 years, and of course radials are
>mandatory with a vertical radiator, but one of the main reasons broadcast
>facilities do not need CM chokes at the antenna feedpoints is: they are tuned
>to one frequency only so the match can be optimized to the point where there is
>little to no CM current.

Thanks.  I forgot to mention that it is helpful to have your matching
network at the feedpoint.

However, I currently tune my inverted L on 1880 with an in-shack L
network.  With 101 radials I don't find a need for any ferrite out at
the feedpoint.

It's also important to note that my comments pertain to ground level
feedpoints and at or below grade ground systems.  It is self-evident
that with many radials, the return current on the feedline will be
negligible since it will be just one among 100 conductors.

I appreciate your comment.

73

Rob
K5UJ


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