[VHFcontesting] Antenna Design Question

James Hayes hazy119 at westelcom.com
Sun Mar 10 17:48:47 EST 2002


Hello all on the list and please forgive the bandwidth...

I'm trying to configure a couple of antenna arrays for 2M and 432. Running
pairs of K1FO-12 for 2M and a pair of K1FO-15 for 432 in the E-plane on a 48
ft tower, and while using Yagi Max I noticed that the wider the W/L spacing
between the antennas the narrower the beam width of the main lobe. Most of
the reading I've been seeing on the subject varies widely regarding the
'optimum' spacing.
The original design parameters by Paul, K1FO states one thing and YM 3.11
states another for optimum spacing for antennas of his design. Also, others
have written that .9 W/L is optimal for all arrays...(confusion sets in.) I
have noticed a tighter pattern on the main lobe provides a cleaner F/B ratio
as well but it lends itself to having the antennas spaced at 1.5 W/L or
larger!!!
My question is rather simple...is it more desirable for one to have a
narrower or wider bandwidth pattern on the main lobe, or is it rather a
matter of aesthetics over gain? As the gain itself does not increase
appreciably to offset the necessity of a narrower band width pattern.

Jim, N2YEV
n2yev at arrl.net





More information about the VHFcontesting mailing list