Topband: 4SQ Arrays in proximity

[Jim Brown]

On 1/28/2020 12:32 AM, Paul F. Merrill wrote:
> HI - I have a couple questions -
> 
> --I am planning a 160m TX 4SQ and another for 80M.   Their centers are
> going to be about 300' apart - is this far enough away?  I have a little
> bit of room to move them apart, but am lucky enough as it is to have the
> space to get this.  The closest verticals will be about 200' apart.

I have no experience with this, but physics suggests minimal interaction 
between the two arrays because of their 2:1 wavelength relationship.
> 
> --I'll be using N6BT vertical dipoles, so there will be no radial issues.

Love this concept. First saw N6LF's take on vertical dipoles, did some 
work on it myself, then saw N6BT's excellent work on it.
> 
> --WRT TX chokes - I'm worried about constructing feedline chokes for the
> feedpoints and still having enough cable (.85vf) 

Paul and I have corresponded directly about this. I referred him to page 
3 of my latest Choke Cookbook http://k9yc.com/2018Cookbook.pdf  and to 
Grant, KZ1W, who initiated and facilitated my work on chokes for 4-sq 
arrays. I also noted Davis RF RG11 (VF 0.84), the 75 ohm versions of 
LMR-series coax, and 75ohm versions hard line like LDF4 or LDF5 (VF 
~0.88) and cables made for the CATV world, where distribution runs at 75 
ohms. All of the Teflon coax cables in that family have VF ~ 0.7

73, Jim K9YC