> Does anybody have any design and/or construction information on a pair
> short vertical antennas without tophats or guys (but posibly with
> amplification at each antenna) for receiving on 160m? I am looking for a
I used to have a 4 element vertical receive array using 30 foot
verticals w/o top hats. Although they were guyed, I could have
put in more substantial bases and dispensed with the guying.
Add a shunt 50 ohm resistor to ground and the antenna now
looks like a 50 ohm source. Build your combining network
using normal 50 ohm hybrids, etc. You can add 50 ohm in/out
amplifiers (make sure they are really 50 ohms) if necessary.
I was able to get by with one amp after the combiner. This
array simply worked perfectly the first time I turned it on.
I have also used 10 foot verticals with amplifiers at each
antenna. You need to use a high input impedance amplifier
(and don't terminate the antenna with 50 ohms). This is
called "voltage probe" mode. This tends to be trickier
to get working right because of the high impedance at the base.
Amplitude and phase matching can be a problem.
Rick N6RK
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