[UK-CONTEST] Verticals

[David, G3YYD]

There are alternate much cheaper way of getting more bands from one 
vertical and without the use of traps, relays or matching units or 
buying overpriced tubing.

Have a look in the index of the ARRL antenna handbook for coupled 
resonators. The main support can be the driven vertical and the other 
verticals are wires spaced to couple with the driven vertical. The 
spacing depends on various factors and an equation is available to 
calculate the spacing, see the handbook, but it can be done by the cut 
and try method fairly quickly. Simple to put the equation into a 
spreadsheet.

I am using coupled resonators for a 80 (wideband), 60 and 30m dipole and 
it works well. The additional bands are at a cost of a few lengths of 
wire. It does not have any loss  or reliability problems associated with 
traps and it has three bands on one coax feeder. It will work OK with 
verticals. 80 wideband means <1.5:1 SWR across the whole of 3500 to 
3800KHz with no ATU, it uses a folded dipole for low end of 80m and a 
coupled resonator for high end. Further resonators for the other bands. 
The additional resonators are supported through holes drilled in the 
folded dipole separators.

73 David G3YYD