[Antennas] Verticals And Trees

2002年9月28日 16:24:49 -0500

>In my many years of operating on the Ham Bands I have found that there are
>actually two types of verticals - the older types such as the Butternut
>HF-6, and the newer types such as the Cushcraft R-7,7000, etc.

Older types = 1/4w as a rule ... Newer types = 1/2w design as a rule
>The Butternut's were originally designed for ground mounting and came
>equipped for that and even their instructions told one how to do such, and
>they worked very well - remember these types of verticals were made to use
>the ground as the counterpoise, and as an after thought Butternut came out
>with a radial system, that didn't work to well when mounted up high.

Indeed ... it made the antenna resonant, but not always efficient. Will it
work, yes ... now how well ... :-) ... "depends" ...
>Now the newer types are designed with built in radials (counterpoises) and
>these are meant to be height mounted - the higher the better and work quite
>well this way.

As the other fellow has pointed, varying the height even with these
designs can give multiple experiences. Keep in mind that "one height"
of say 20' ... that's not the same height in terms of wavelength for all
frequencies. Example? Let's say that 20' up works "best" for 20m,
to get the same performance (take off angle/etc.) on 10m, then the
height should be 10' ... or 40' for 40m ... <these are just numbers>
So keep that in mind when swapping notes ... what band, how high, etc.
> For what it's worth! Ron, N6PWW

Very good summary Ron ... comparing the 1/4w design with 1/2w design.
Even 1/2w designs benefit from a ground plane, check out the WWVH
antenna site on the web ... 1/2W vertical ... salt water ... AND a radial
system.
73 Billy AA4NU