R: Topband: Re: Folded Unipole vs Series Fed Antenna

[Maurizio Panicara]

This kind of antenna is definitely unefficient and it's not any more a
folded unipole in most of its range.

Actually,  for most of the octaves of the planned use, you were dealing with
a sort of small and stretched magnetical loop exibiting a small area and a
big conductor loss compared with the inherent Rr.

In a slight/moderate shortening than a quarterwave, the arrangement of a
fold unipole (or a tap along a tower) feed doesn't have any bad effect
compared to a series feed but allows instead the use of inherently lossles
devices, like vaacum capacitors, to obtain the required slight loading and a
confortable match at 50 Ohms.

The only way to recover efficiency in short verticals is a big capacitive
hat and a proportioned ground plane, surely it's not a base coil in a series
feed short whip that fixes.

73,
Mauri I4JMY




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