Jim, wouldn't you think that the 20m yagi would suffer pattern degradation
while the 80m yagi would be ok?
73,
Gerald K5GW
In a message dated 10/6/2010 7:35:00 A.M. Central Daylight Time,
jim.thom@telus.net writes:
How close can you get a 20m yagi, below a 2-el 80m yagi ?
I have an option to use a F-12 Sigma 280-S shortened 80m yagi
at the top of the mast, with the F-12 340N at the bottom of the mast.
Spacing between the two of them would be 10.5' If possible, I
would like to sandwich my F-12 520 [20m yagi] between the
80 and 40m yagi. Apparently, you can mount any other F-12 HF
yagi within 36" of the 3-el 340N yagi. If I put the 20m yagi
4' above the 40m yagi... that would leave 6.5' between the 20m yagi
and the 80m yagi. Will this work ?? If it doesn't, one option is
to remove the 20m yagi. Another option is to place the 80 and 40m
yagi's at right angles to each other [ no 20m yagi at all] . I don't
think this
is required, but would minimize the total wind load.
Plan B would be to replace the 2-el 80m yagi with a
80m rotary dipole...with dipole inline with 20m/40m booms below it. IE:
dipole
is then at right angles to both yagi's below it. Due to day time height
restrictions,
the above options are strictly an after dark scenario. I don't have any
software on hand
to model any of the above.
Thanks.... Jim VE7RF
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