[TowerTalk] Phased Vertical Follow-up

[Terry Conboy]

On 2009-03-13 11:32 PM, N7mal wrote:
> A friend of mine asked me about the 14AVQ vertical. I wanted to 
> re-familiarize myself so I looked it up on the Hy-Gain website. At the 
> bottom of the manual is a Hy-Gain addendum. It is anything & everything you 
> ever wanted to know about phasing multi-band verticals.
>
> http://www.hy-gain.com/man/pdf/AV-14AVQ.pdf
>   
The phasing section of this document has been around since the 1960's, 
if not before.  It was developed long before most hams found out about 
the interesting effects of mutual coupling on the feed impedances of 
closely spaced verticals.  The 0 &180 phasing schemes will work OK, but 
the 90 degree phasing arrangement will be quite sensitive to line 
lengths.  It will probably get reasonable gain over a single vertical, 
but the back nulls will often be poor.  Of course, the more loss in the 
traps, the better the patterns will be (as long as you don't mind the 
low gain).

73, Terry N6RY