Robert L. Shohet wrote:
> Let's say that I am going to stack 3 4L 15 meter antennas on the same
> band that are gamma matched with roughly the same pattern, resonant
> freq. and vswr. But due to the heights of the antennas and the guy wires
> I need to do the following:
>
> 4L long-boom design res. 21.225 27 ft boom @ 90'
> 4L res. 21.225 20 ft boom @ 60'
> 4L long-boom res. 21.225 27 ft boom @ 30'
>
> Is this idea ok? Or is it better to use 27' boom at 60' even though
> when rotated it will be within 18" of the guy wires at certain beam
> headings?
It will be better to use IDENTICAL antennas in the stack. 18 inches is a
mile in these applications!!
> I plan to use 1/4" EHS rather than Phillystran.
Better break it up with insulators per the Handbook or use fiberglass guy
rod (see my home page: http://www.erols.com)
>
>
> Question #2
>
> What is the minimum height (based on personal experience not
> manufacturers suggestions!) that you would recommend spacing a 2L
> Cushcraft 40-2CD above or below a 4L long-boom Cushcraft 4L20?
The minuimum spacing I use between my 402CD and HiGain 204CA is 17 feet.
But, you can model your situation and determine what interference level you
would accept exactly.
>
>
> My gut tells me that I want about 8-10' spacing but I am not sure. Any
> ideas on this?
>
> Tnx!
>
> Bob KQ2M
>
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