Stuart,
What is a Wheeler Cap Efficiency Measurement? Is this covered in the ARRL
Handbook or Antenna Book?
73..de John/K4WJ
At 04:31 PM 4/18/02 -0500, Stuart Rohre wrote:
>Hi Tom, I NEVER claimed the folded conical Helix was better than all other
>antennas, I said it was more efficient than some small antennas of
>comparable volume which it is. The Isotron and most other small ham antenna
>designers for example, have NEVER published Wheeler Cap Efficiency
>Measurements, nor have I seen those on the EH web site. I have not seen a
>16 inch loop for 10m measured by the Wheeler Cap, but think that would be
>instructive for us to do.
>
>I have received other emails confirming that some small loops are only 10
>per cent efficient. By definition of Wheeler, Bob Rogers is concentrating
>on antennas in the kr range of 0.1 to 0.01 ONLY at this time. As we all
>know, how you build a small vertical loop is all important in its
>efficiency, and to tune it you have to have a lossy component, and
>minimizing that loss is the major part of the loop battle. Small loops can
>be made to work, but certainly do not have a 10 per cent bandwidth at
>several bands as does the Folded Conical Helix.
>
>The Cone appears optimum at this time, for getting a resonant length of
>folded element into THIS volume, without excessive blockage of radiation
>from one element and neighboring elements, and having something with low
>angle radiation, vertically polarized.
>
>With all due respect,
>Stuart K5KVH
>
>
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73..de John/K4WJ
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