The normal innocent presumption would be that your feedlines and other
miscellaneous conductors are not involved in your patterns. But if your L
and your 6BTV are engaged in a horse race on 160, your tower/L is really
not doing well, and has the typical loss problems for that setup.
My personal inverted L is out in the woods away from everything, without
radials for that matter, uses an FCP. It simply blows away anything I have
ever used on 160 on this property, nothing close. There is nothing
intrinsically inferior about an L. Yes there is something about a few
tenths of a dB down from a completely vertical 1/4 w radiator, but your
case sounds more like 5 dB lost or 10 dB lost.
You are likely hearing a LOT off the OTHER feedline shields (because they
are also close coupled to the L vertical) and effected by miscellaneous
conductors in the vicinity. You shouldn't have any real expectation of a
clean vertical doughnut pattern, and miscellaneous conductors NOT sturdily
blocked for common mode current will have you listening everywhere,
including to all the garbage on the safety wire of your house wiring.
73, Guy.
On Sun, Apr 29, 2012 at 8:51 AM, Lloyd Korb <k8dio@roadrunner.com> wrote:
> To everyone how replied to my Inverted L question, a big THANKS! I really
> learned a lot from the replies.
>
> I know that what I have is not an ideal situation for the Inverted L but
> it's all I have available to me. I live on a very standard one third of an
> acre city lot. My 60 foot tower is used to support a multitude of VHF/UHF
> yagis used for weak signal operation. Prior to a friend giving me an old
> 6BTV vertical, last year, the Inverted L was my best shot for getting on
> 160
> meters.
>
> As one fellow said, "If it's not broke, don't fix it". It is a great
> antenna for me. I am able to use it on 160 through 10 meters using my
> tuner. Maybe ignorance is bliss!!
>
> What is interesting to me is the fact that at times the L seems to have a
> different polarity than the 6BTV. I can switch back and forth between the
> two antennas, on bands other than 160 meters, and see quite a difference in
> signal strength. So, If the L is actually just inducing current to the
> tower, on 160, it should be vertically polarized. Then I really shouldn't
> see a difference between to vertically polarized antennas! Could this
> difference be because of the horizontal part of my Inverted L radiating!
>
> After being a Ham for over 55 years I'm still learning something new!
>
> Thanks again for all of your replies.
>
> 73, Lloyd K8DIO
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|