I have modeled some phased K9AY loops, and found that 180 degree phasing with
loops facing (receiving) the same way, at 130-foot spacing gave some
interesting results, in terms of a narrower pattern with better F/S and RDF
roughly like a 1.5 wavelength Beverage. The phasing is a lot simpler than a
4-square. I used one of these pointed NE last year with good results, though
I've never used a good Beverage so I don't know how it compares. I'd be happy
to share the model with anyone who wants it.
I have designed, but not yet built a 4-way array using 3 K9AY loops - two
single plane (bidirectional) and one of the traditional 4-direction type, on
two adjacent sides of a 130-foot square. I notice that SP9P speaks of modeling
results - perhaps he would be willing to share his model in either EZNEC or
NEC-2 format, and we could draw our own conclusions.
The original K9AY article speaks of compromise terminating resistor values for
80 and 160.
At 08:02 AM 12/19/2006, Jim Jarvis wrote:
>Joe, SP9P's report on the sp3key quad-phased K9AY loops is
>interesting, and prompts questions.
>1) Has anyone modelled this? What is the resulting
>pattern, in any one direction?
>2) I would assume that the pattern is tightened, and f/b
>improved. Does this result in front-side coverage holes?
>3) My crossed AY loops worked ok...and had deep nulls, but
>only very seldom did an offending station land in one. As
>a result, I concluded that ONE AY loop, rotatable, was better.
> Is that same effect noticed at sp3key club?
>4) The discussion doesn't talk about frequency. Yet the loop
>terminations need to vary, to optimize performance at 3.5 or 1.8.
>What provision is made for 'tuning' the loop termination?
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