Topband: Bruce arrays

[Grant Saviers]

Wondering what experience there is for 3L Bruce arrays and if a 
reflector has been tried?  It looks like a good "bang for the buck" way 
to get some low angle gain.  My interest is to 80m to improve low angle 
(5-20deg) versus a 86' rotatable dipole (Tornado tuned 
redesigned/rebuilt EF180C) at 100'.   The goal is a better signal to EU 
from Seattle, a tough path vs the W1's.  I have some free antenna 
supports in the form of 100' hemlocks and cedars with the right 
orientation and the highest support rope can be about 90' agl.

I've run a bunch of EZNEC sims which show 18deg gain improves by 1.1db 
and at 10deg by 3.6db for the 3L Bruce with its top at 80'. Helpful, but 
not dramatic.  Very wet winter earth here is a bit better than average,  
I use 0.01ms for ground conductivity.

I think it is mechanically feasible to add a close spaced passive 
reflector, 25' separation.  Then the sim'd gain improvement vs dipole is 
4.1db at 18deg and 6.9db at 10 deg  and 10.1db at 5deg (my QTH has a 
good EU HFTA) over the dipole.  That is really getting interesting, but 
I am wondering how much to trust EZNEC with such close spacing ~0.1wl.

I have no place to put radials for a 80m 4 sq transmit antenna, and the 
cost would be a LOT more if I did.  I've modeled phased delta loops hung 
from a 90' tower, but the reported tuning difficulties and sim'd tower 
interactions are a big concern plus poorer low angle gain.

Inputs and better alternatives appreciated.

Grant KZ1W