TopBand: verticals

[Peter Chadwick]

> *	I have very good success with a grounded tower fed as a folded
> unipole. It has the advantage that the radiation resistance goes up,
> minimising ground losses.I use a crank up at 60 feet, top loaded with
> a 5 ele for 20, and interlaced 4 eles for 10 and 15 at 68 feet. I feed
> it with 3 parallel wires spaced about 10 inches from each other, and
> bond all the coax outers for the beams top and bottom. An L match
> requires no readjustment over the band on 160, although on 80, it's
> very sharp tuning and runs lots of volts. Adding radials gave no
> change in input impedance ( <1%) and no measurable current in them
> with 400watts and a 250mA thermo ammeter in the radial. This suggest
> that the ground currents are low. The subsoil is heavy wet clay, and
> the grounding is three 4 foot ground rods. It works - VK0IR 2nd call
> on 160, 1st call 80 SSB. I spent a long time trying gamma and omega
> matches until going to the folded unipole approach.
> 
> 73
> 
> Peter G3RZP
> 

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