>
>Tommy, you have me here. What is the "spaced 8'" pertain to. And
>perhaps on a point of interest, a Zepp as described is an Extended
>Zepp, not
>a Extended Double Zepp, which requires 2 wire sections on each side,
>with appropriate phasing lines. ( I use 450 ohm open wire line ) If
>the
>antenna is then fed in it's center point with another section of open
>wire line, of X length, and the bottom ends connected to a balun, you
>may achieve almost a perfect match to 50 ohm line.
Ed....
'A picture is worth a thousand words!' If you will, look here for
pictures of the EDZ yagi:
http://tom.w4bqf.googlepages.com/home
The Antennas page shows a photo of the wire yagi plus the EZNEC plot
and the spacing between the driven element and the reflector is 8 foot.
>Ever tried pointing a 33 degree beam width where it provides max
>population coverage into Europe?
>
>
>This is a very good point. I believe from memory that our heading to
>EU is about 57 degrees. So, that gives us a good starting point.
>However, and this is a problem I am still studying, what is the
>optimum
>take off angle for such an antenna? Most books or authors state that
>over 90% of the times, the arrival signal from EU is 20-23 degrees.
Yep. I noted in the 2005 PVRC Contesting Seminar on DVD that W3LPL
was stating the same thing, 20-23 degrees for Europe and something
like 15-18 degrees for Japan/Asia and noting that at his location,
optimum heights for those angles were in the vicinity of 95 to 110
feet, as opposed to those four 200 foot towers he has.
>73
>Ed
Tom - W4BQF
|