Modeling I've done shows it a bad idea to have in ground and elevated
radials connected together, but that is not clear from what you
described. Then with the elevated separate, moving the feedpoint up at
least 8', to 12' is better and elevated radials run out at that height.
I think it is a tossup if the "flying V" feed is used - ie gain some
vertical wire length by feeding near ground and then angle the wires to
the the elevated ones say at 45 degrees. It doesn't hurt to have the
buried radials below the elevated but doesn't help either according to
NEC4.2 models I've tried. The elevated ones shield the currents enough
from the ground in the near field.
Check out what N6LF has to say about elevated radials (if you haven't
already) antennasbyn6lf.com
Then develop an swr curve with 5 watts from your rig. Better than nothing.
Borrow a different antenna analyzer to try or put a quality BCB filter
on the input. You need one anyway. A two port VNA can calibrate out
the filter.
It is also hard to compare antennas unless the A/B testing is real time.
This week proves that on 160, one night nada to EU, Thur night was
pretty good and I missed the killer opening on Wed according to PNW
reports.
Grant KZ1W
On 12/28/2018 15:35 PM, Todd Goins wrote:
I originally started this thread and I want to once again thank everyone
who provided input and advise both privately and on the reflector.
So the 100' tall vertical with the 30' horizontal loading wire works
**horribly**. I have about a week with it now every evening and it is much,
much poorer transmitting (and receiving, as expected I guess) than the 43'
vertical with the 90' horizontal.
Since everyone was united in the opinion that I needed a dedicated
receiving antenna I put out a 200' BOG (pointing east) with the transformer
and terminating resistor from DXEngineering. The BOG is really quiet
(S1-S2) compared to the verticals and it hears "okay" but I wouldn't say it
was great by any means. The Stew Perry tomorrow will give me better chance
to evaluate it.
Back to the 100' vertical. Since it wasn't working being tied into the
buried radial field I was using for the 43' (PSK Reported showed dreadful
performance) I decided to take a different approach and made it have an
elevated feed point at about 7' above ground and I ran three 130' elevated
(also around 6' to 7' high) counterpoise wires. This antenna works a little
better but still not nearly as good as the 43'.
Several people asked me to make R/Z measurements of the antenna at the feed
point. I'd love to provide that info but my Comet CAA-500 MarkII antenna
analyzer is being totally killed on 160m by a 27.5KW AM broadcast station
that is about 2 miles from my QTH. It will not work. The analyzer has been
fine on 6-40m and sometimes works on 80m but 160 is no-go. So I can't get
the reactance and resistance values you all wanted.
So, here is my question. The one easy modification I can make to the
antenna, now that I have elevated radials connected, is that I can elevate
the feed point. I can raise it to about any height necessary. Would this
make any difference? I would lengthen the horizontal wire by whatever
distance I raised the feed point, right? Any ideas or am I just chasing my
tail?
Thanks for reading and any advise you can give.
73,
Todd - NR7RR
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