On Dec 1, 1:42*am, (Richard Harrison) wrote:
Art wrote:

"I stated "intuitively" since the radiation is axia with respect to the
helix."

A 3 M diameter has about 9.42 M circumference so becomes an effective
axial radiator instead of a radial radiator at the frequency near where
its circumference becomes one wavelength. This frequency is
300/(pi)(diameter) or about 10 MHz. A reflecting surface to make an
axial helix unidirectional needs to be at least as large as the
projection of the helix on the surface of the reflector. Its diameter
should then be about 3 M or more and would be effective only at
frequencies exceeding 10 MHz which is where the helix becomes an
end-fire device anyway.

Best regards, Richard Harrison, KB5WZI


Richard
That is good information that has a trend to my way of thinking.

A heads up as to where this information comes from would be very
helpfull to
me in my on going experiments

These ratios of diameter to length does have a penalty in wavelengths
used
but hopefully in less reflector diameter which is not to be viewed as
a phase enabling point of view
If one viewed a helix as an array of loop radiators then phasing would
be important but then prevents
the formation of smaller volume radiation designs. For those who rely
solely on "off the cuff" thoughts
may well deride what I am doing but I have done my homework and am now
pursueing implematation
since experiments consist of more than the exercises of the brain
without the need of personal observations,
without which advances would be crippled and science laboratories
would become extinct
My thinking now leans toward solenoid style with a air bound core for
maximum flux density
within the core in "rifle shot" pattern. I have had a similar antenna
for the 80 metre band where the helix diameter
is just 4" which is quite directional even tho as low as 30 feet!.
Thus I am very much encouraged in
this new design which is light enough for me to carry and install
together with improvements added over my past effort
tho it will not have the tilting feature at least not in the near
future. I am anxious to add the tilting feature some time next year
in an effort to extend individual QSO time as propagation changes ,but
it is low on program requirements
Best regards
Art Unwin KB9MZ..........xg