Andy,
Some time ago, I also did extensive modeling of resistive-loaded verticals,
hoping to find a configuration that had good broadband characteristics and
moderate loss, or at least a method of construction that simplifies the
matching network -- but no luck. I did not find anything that was a
signficant improvement over a simple vertical with the input swamped with a
resistor.
In the process, I did discover an antenna with a good hemispherical pattern
(omnidirectional in both azimuth and elevation) -- two K9AY Loops placed
side-by side (in parallel, spaced several feet apart), oriented in opposite
directions and fed with 180 deg. phase shift. This might be useful for
something, since hemispherical patterns are typically hard to obtain.
73, Gary
K9AY
> Good morning Guys,
>
>
> It is possible to achieve the same reception pattern of a ground mounted
> vertical using a 22ft aluminium pole with 2 sloping wires affixed to the
> top of the pole? Each wire comes out say 15ft from the pole ( 5ft above
> ground ), then bends back towards the base of the pole and is connected
> to a ground rod via a 1k resistor i.e. the antenna looks like a single
> K9AY loop with 2 termination resistors. The insulated 22ft aluminium pole
> and the ground would be connected to a high Z input bipolar buffer
> amplifier with common mode feeder isolation choke.
>
> This configuration ( if it works) would provide lower noise than a FET
> active vertical with higher immunity to static damage! Also the amplifier
> would see a resistance loaded antenna rather than a small capactance of a
> whip antenna.
>
> 73
>
> Andy G8LUG
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