GEORGE WALLNER wrote:
>
>
>
> Niko Cimbur <ac6dd@yahoo.com> wrote:
>> Can something like this be easily done?
>> I am not familiar with the two 750W amps they have, but
>> Would it be possible to build a 4 square and feed each
>> element with its own amplifier and switched phase delay?
>
> Niko,
>
> I have done this with a two element array and it worked
> great. Phasing control is much easier at low power levels,
> i.e. ahead of the amplifiers. You have to ensure that each
> antenna is matched properly. (I used LC matching
> circuits.) Driving a 4SQ is more complex but should be
> possible.
>
> George, AA7JV
How did you determine it worked great? In most two element
arrays the impedance of the rear element is virtually a
short circuit. The second amplifier goes to waste as it
cannot deliver any significant power into this load. You
basically lose 3 dB compared to using a hybrid combiner to
make the two 750W amps into one 1500W amp and then using a
conventional feed, like a W7EL feed.
Rick N6RK
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