Has anyone vertically stacked a pair of 5 band hex beams? Feedback? Thanks.
I have not vertically stacked a HexBeam Antenna, but plenty of yagi arrays.
First, vertically stacking, while not exclusively done, is mostly relegated to monobander antennas. This is because the 2nd antenna is tuned
to the 1st to take advantage of the reinforcing amplitudes generated by each antenna. The distance between them is primarily determined by which band you select and secondarily to the the antenna's gain figures. To produce the additional gain (a maximum of ~ 3db) requires a specific
RF relationship between the two antennas. For example two M-Square 4 element 20M yagis have a stacking distance around 56 feet; other M-Squared 4 element yagis have significantly different stacking distances based upon their frequency of operation.
Moving the stacking distance a few feet either side of the recommended stacking distance will not substantially hurt their performance; but, if you stacked those 20M yagis (cited above) at 15' apart, they would not work properly and would actually perform worst than a single yagi.
I've read about a few operators who have stacked triband yagis (10M, 15M, and 20M) at a distance apart based on 15M operation and they have reported "very good" performance on 15M and "decent" performance on 10M and 20M. IMHO, I don't think that you'd see this when using a HexBeam.
Perhaps G3TXQ will chime in on this ... he's much more familiar with HexBeams than most of us (especially me - hi).
GL, 73, Rich, K3VAT