Good evening Guys,
I would like to thank both Terry and Gary for their off-line and on-line
response to my question posted below.
> 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
Terry was very kind enough to model the above idea and with a 500 Ohm shunt
on the amplifier input. Both models provided a typical vertical Elv. and
Azi. pattern. However, dual termination provides a much lower capacitve
reactance compared to the 500 Ohm shunt from 0.5 to 2MHz. Thus I believe,
the dual termination will be ideal for driving a tranformerless unity gain
bipolar buffer amplifier. This hopefully should provide some additional gain
and with a well defined phase charateristic for use in wideband endfire
arrays?!!
73
Andy
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