Sorry for the long and rambling post. . . .
OK gang, I know antennas "fairly" well, but this has me stumped...really
REALLY stumped. I've beat myself up over this for 2 yrs. straight. I just
can't get it. I am (almost) ready to rip everything down and start from
scratch)
I posed a ~similar~ question last year and have tried some different things,
but I'm losing my patience with the wire here (hi)
BACKGROUND:
At my old QTH, I ran an inverted L...5/16thWL and fed with a 800pF cap in
series. A dozen to two dozen 1/4wl radials(depending on how many got broken
in the summer)over soggy ground. It meandered up 50-ish or so feet with the
remaining 117' up/down/over/under trees --even the tip sloped back towards
the ground 20' or more.....and it ROCKED....I mean, I wasn't any VE1ZZ or
anything but I felt I was upper middle crust of the W1/VE1 pileup. I also
had the exact same tower and exact same Alpha Delta DX-A twin sloper up (for
reference) and it s*cked...really bad. Easily several S units below
anything else on 40-80-160m
NOWADAYS:
Fast forward to new QTH...same 48' DElhi self supporting tower set in
concrete....same 2 long 6m yagis on tower (48/64')....same lil' sloper
mounted @ 24' off side of tower....
I have tried 2 iterations of a plain inverted L.....currently it's a "T"
antenna. Sloping 55' or so up and 2 T's @ 55' or so each sloping @ aprox 45º
to the ground....loads nicely with a few uH @ the base. Seems quieter than
the A-D twin.
I have tried shunt -and- series feeding my 48' tower (no problem to do).
They have all loaded well and I got a good SWR match with a usually narrow
window 50Kcs maybe of 2.1:1 SWR of which to operate in. I have 25 or so
1/8wl to 1/4wl radials - 1" below the grass. Ground is rocky shale? sort of
stuff. My QTH is on a nice high ridge and I do quite well on VHF and other
HF bands.
My signal is pitiful on **all** the 160m antennas I've tried....with the
exception of the 1/4WL Dx-A twin sloper @ 24' !!! (it's best but it barely
works)
The little/low twin sloper off the side of the towe is ALWAYS the loudest on
the band....by usually 6dB or more........I know this can't be right.
How can this be? I am using a 4-1 antenna switchbox (Ameritron I think) @
the base of the tower which the antennas all share. Many years back I
modified it so all antennas "floated" (instead of being grounded) when not
selected as I was using this as a K8UR sloper system switchbox at one time.
I am pretty sure (but not 100%) that I even ran a separate chunk of coax
right out to an inverted L last fall in desperation. I do lots of antenna
experimenting, so it's sometimes hard to remember the 45th iteration of a
trial I had a couple years ago, hi.
I *DO* notice significant SWR curve changes on the lil' wee sloper if I make
any mods to any of the other "REAL" 160m antennas.
I either have interactions in the switchbox, or proximity between antennas
or something that I am totally missing. All 160m antennas are quite close
(less than 20-30' away).
Logic tells me there is no way in heck the very low Alpha-Delta DX-A twin
sloper can __always__ be the best antenna to transmit and receive on. YET
is is !!? From what I see on the cluster, web and hear on the air, I can
hear quite well, but DX stations normally have to be 559-579 before I even
get a QRZ.....I am currently running ~750W.........
I'm cracking up.....too much listening to QRN.......sorry for the long post.
Thanks for any insight. I am ready to put a Webster Bandspanner on my
mobile and go sit out in the yard and DX.
<hi>
VE9AA Mike
Mike, Coreen & Corey Smith
699 Rte 616 Keswick Ridge
NB
Canada
E6L 1T1
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160 meters is a serious band, it should be treated with respect. - TF4M
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