[Elecraft] easy simple portable antennas?

[Vic Rosenthal]

kc4kgu@ENTERZONE.NET wrote:
> 
> I looked into this antenna a few weeks ago.  From everything I can find
> with testing, it acts like any other short, fat dipole.  IE; It is not a
> very efficient radiator.  Sure, it will load up.  That is a function os
> the loading coil and the capacitance between the two elements.  It doesn't
> appear to radiate nearly as well as a *low* half-wave dipole
> though.  

I agree that the theory on their web sites is B.S.  It is a short dipole with a
lot of capacitance between the elements.  As such, it could be efficient IF (a
big IF) the resistance of the coil used to resonate it could be made low
enough.  The problem with short antennas is that the radiation resistance is so
low that any ohmic resistance in the antenna and coil is comparably large and so
wastes a lot of power.  I think that a reasonably efficient antenna could be
made for 20 meters or higher, if the coil were made out of copper tubing and
properly joined to the dipole elements.  Perhaps a 6-foot long antenna with a
coil of 1/4" tubing (in the middle, not at one end) would be practical.  Of
course I would expect the bandwidth to be quite narrow as well.

73,
Vic, K2VCO
Fresno CA