I've used a three beverage broadside array aimed NE on 160m for the last
4 years or so and it works very well. Each beverage is 1000ft (304m)
long and spaced about 300-310ft.
For best results on 160m, the spacing should be at least 300ft between
beverages and the outer elements reduced to 1/2 voltage (1:2:1 binomial
feed, cleans up pattern knocking down side lobes). You can accomplish
that with 6dB attenuation pads on each of the outer legs, or one pad
after combining the outer elements. Resistor values for the 6dB pad(s)
should be chosen for the circuit impedance wherever you decide to place
them. All elements are combined in-phase.
ON4UN's book has some info on this regarding a 4-el broadside vertical
array (Ch. 7, Fig. 7-29), which is fed 1:2:2:1.
73 Eric NO3M
On 9/11/18 11:27 AM, Herbert Schoenbohm wrote:
I use DXE 9:1 beverage transformers and DXE 470 ohm termination
resistors.
I brought 150m (500ft) 50 ohm cable from each beverage feedpoint to
the shack and connected to Microham Stack Switch (like Stackmatch).
All the cables were of identical length to ensure same phasing.
So I presume this system gives me full ability to test any combination
of those 3 beverages alone or phased with each other?
Well, all the 3 beverages alone are quite identical indeed which is
good.
But now when switched in pairs or all 3 together I am not seeing much
effect. I do know what the patterns should look like and I presumed
the effect would be strong especially with signals coming from side
but most of the time I notice no difference with any signals when
comparing any single beverages to combinations.
This is puzzling. Modelling suggests I should for example have very
big improvements in suppressing signals 45 degrees off on 160m when
using 2 phased beverages 120m apart as well as when using all 3
beverages on 80m but I did not notice such drops of 10-20db almost in
any signals from any off directions.
I could hardly notice sometimes the expected 3-5db increase in the
signals from the right direction but not always as well.
Can some of you having experiences with phased beverages tell me if I
have done something wrong in my setup?? Should I test them
differently? Are the phased beverages overrated and in real life there
is seldom a significant improvement over 1 single wire beverage that
is already long enough like 220m in my case?
Look forward to any input. I can send the modelled patterns and maps
of my beverages in picture files to anyone interested.
60m (your separation) is about 3/8 wavelength on 160, and the elements
are long (1 1/8th wavelength) so they'll interact signficantly, even if
disconnected from the feed (just like parasitic elements on a Yagi).
How high off the ground are the wires?
How did you model the switching?
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