[Lowfer] a thought on coils

[Ashlock,William]

Ed,
> 
>> 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
>istribution is altered to increase the current in the upper portion.

This is a strong argument only if the top hat capacity is minimal and the
pole capacity dominates. The hat capacity on a typical Lowfer antenna is
much higher than the pole capacity and there is only a small additional
amount of inductance needed when the coil is moved up close to the hat. The
signal strength at a distance is proportional to the effective height. The
theoretical ratio of signal from a top loaded antenna vs a base loaded
antenna (assuming plenty of hat capacity) is almost 2X!

Bill   

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