Topband: 160m vertical with "top loading"

[GeorgeWallner]

On Sat, 23 Apr 2011 16:05:24 +0000 (GMT)
  k3bu at optimum.net wrote:
> On the subject of resonant loaded radiator - element 
>please see my article at
> http://www.k3bu.us/loadingcoils.htm
> it took me some 40 years to realize wasaaap with loaded 
>elements - current distribution and efficiency.

Yuri,

Regarding the current in a loading coil, of course you are 
correct. A inductor inserted into a vertical will have 
higher voltage (ref to GND) on its "upper" end. If the 
current remainded the same as on at "lower" end, there 
would be more power on the "upper" end. Not likely.

Another way to look at this is that the inductor is part 
of a Pi network, the two capacitors being the two halfs of 
the antenna. At the top is the higher impedance port, 
where, for the same power (discounting losses), the 
voltage is higher and, by definition, the current is 
lower.

Any one of us who has ever touched the top portion of a 
center loaded mobile whip during transmit can attest to 
that higher voltage!

TKS for the excellent paper,

73,

George, AA7JV