Jim, yes, I suspected they might interact of course. But can I avoid it?
ungrounding both ends of the unused beverage would also not eliminate coupling
I am afraid?
Height is ca 2m +/- 0.5m.
I did not model switching in any other way than simply creating feedpoint for
both beverages. No feedlines in the model. Could such long feedlines even if
the same length, create a trouble?
On 11 Sep 2018, at 15:19, jimlux <jimlux@earthlink.net> wrote:
On 9/11/18 5:00 AM, Tonno Vahk wrote:
> Hi,
> Last weekend I finally got into experimenting with phased beverages,
> something I was planning for some time.
> I installed 3 broadside 219m (718ft) long beverages into the forest looking
> at 90 degrees and separated 60m (200ft) from each other (120m between the
> outer ones).
> I took great care to make sure the wires are straight and fully parallel to
> each other as well as starting from the the same line.
> 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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