K9OM wrote:
I am looking for the best way to feed a 1/4 wave Vertical with the
following
in mind:
1) QUIET RECEPTION: will a tower being used for receive as well as transmit
be quieter if the base is grounded and shunt-fed rather than insulated from
ground and base fed?
No. They will be the same.
2) RADIATION EFFICIENCY: assuming the same ground conductivity and radial
system, is there any improvement in radiation efficiency between a
grounded shunt
fed vertical and a base fed tower?
No. They will be the same.
Such as, would the shunt feed raise the
current radiation height and therefore less ground loss?
No. They will be the same.
That assumes both towers are the same height. A shunt fed system is
nothing more than a matching network. Antenna efficiency isn't
significantly effected by a matching network unless that network is
poorly designed and has high losses. Ground loss is determined by the
amount of current going into the dirt. That will be the same for both.
Nearly all antennas on the low bands are noisier than most people would
like, so for those bands think receiving antenna.
Jerry, K4SAV
RLVZ@aol.com wrote:
>Hi Guys,
>
>I am looking for the best way to feed a 1/4 wave Vertical with the following
>in mind:
>
>1) QUIET RECEPTION: will a tower being used for receive as well as transmit
>be quieter if the base is grounded and shunt-fed rather than insulated from
>ground and base fed?
>
>2) RADIATION EFFICIENCY: assuming the same ground conductivity and radial
>system, is there any improvement in radiation efficiency between a grounded
>shunt
>fed vertical and a base fed tower? Such as, would the shunt feed raise the
>current radiation height and therefore less ground loss?
>
>All thoughts appreciated!
>
>73,
>Dick- K9OM
>
>
>
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