[Lowfer] a thought on coils

[Ed Phillips]

Ashlock,William wrote:
> 
> John,
> 
> Very interesting! I would expect the dual pie windings would do fairly well
> by themselves and have almost enough inductance without the ferrite core.
> The HV winding on a TV flyback transformer would be similar and is not
> influenced that much by the core. It's possible that Walt used the core more
> for tuning than to reduce the total number of turns required. There would
> certainly be much less magnetic field intensity in his core compared to a
> core that is wound over its full length. It could also be that Walt used a
> ferrite with a low permeability having a higher saturation value than
> commonly used cores.
> 
> I like the idea of placing the loading coil close to the top hat. This
> maximizes the effective length of the antenna and reduces the effect of the
> stray capacity from the vertical portion to the lossy soil.
> 
> Bill

	That would be true if the loading coil had very low losses. 
Unfortunately, as the coil is moved toward the top of the antenna the
capacitance which it is tuning gets lower, requiring a higher inductance
with attendant increase in series loss resistance and potentially
negating the benefits of increased effective height as the current
distribution is altered to increase the current in the upper portion.  I
am not aware of any quantitative measurements of this type, but a number
of years ago Bob, K6QAY built several lowfer antennas with this
configuration, tuned by a variometer-type variable inductor which was
controlled at the bottom by means of strings.  I could never observe any
increase (or decrease) in his signal at this location, about 25 miles
away.

Ed