Hi Richard,

Of course, when the inverted L was fed with both shield and center conductor
shorted, that is a short. But I also tried feeding just its center
conductor..and it was poor, as it should have been. I'm not saying that the
CW-80 center conductor only, brute force tuned was a great antenna, just way
better than I had any right to expect. It's not like 160 is like 10m, where,
when the band is up, nearly anything works. 160 is notorious for exposing
poor antennas.

In any case, without a legitimate reference antenna, I am limited to "how
well do I get answered and at what distance" analysis and that's what I
tried to provide.

A test I would like to do sometime is to get a KW-80 trap, put it on the end
of the 80m L and extend the wire out for 160m resonance. Then I would have a
2 band inverted L and that would be a reasonable reference antenna. What has
kept me from this is I had a hard time finding the KW-80 traps...they were
out of stock. My other concern is since the 80m inverted L works so well, I
don't want to do anything to ruin its performance. (It's also hard to get
motivated to go out and do the raising and lowering and tuning in the middle
of winter, yet if I don't do that, there won't be much I can do to evaluate
the trap's effect on either band.

I was trying to get "something" for nothing with the CW-80 trick, and
succeeded beyond my wildest expectations. Nothing about my situtation could
allow anyone to duplicate what is happening here. Too many variables. I just
got dumb lucky, and THEN I get curious. I still think this arrangement
should not work very well, and that just isn't the case. The goal was to get
on the contest and make contacts as if I had a "good" antenna. Anyone who
does contesting knows what a "good" antenna feels like as you call stations
and listen to those being called. It is so easy in a very few minutes in a
busy contest to accurately conclude: this antenna is crap. I couldn't do
that and was mystified as to why not.

Either this antenna was working as some sort of kludgey inverted L or
somehow the tower was getting excited, or both. Whatever set of fortunate
circumstances obtain, if I were to have put up a "proper" antenna for 160
and gotten the results I did (and if those results were/are repeatable), I
would have said, "This thing works pretty well." I then became very curious,
and that is all. As you noted, without a reference antenna, a real
assessment is impossible. However, how the antenna performed on the air in a
situation that is well understood (contest environment) made for some raised
eyebrows on my part. Rarely does "loading up what is laying around" work. In
this case it did. Antennas and propagaton obey the laws of physics. I'm just
wondering which ones apply and in what manner for this particular
"arrangement".

I'm left with the question, just "what kind of an antenna" is this, or does
it "resemble", that would perform as well as it did.

Radio signals and how they propagate still resemble "magic" at times, yet no
one in their right mind would build the mess I was brute forcing my RF into,
nor would I recommend it. At the same time, if one just "has" to get on the
air in a hurry, my experience might prove useful. If there is one thing I
learned from this it is don't dismiss something out of hand without trying
it (if there is an urgent need). You may get surprised. Then if it works
well, try to explain it later (if you are curious...and I am.)

Thanks for your comments.

73,

....hasan, N0AN
"Richard Clark" wrote in message
...
On Tue, 31 Jan 2006 16:14:38 -0600, "hasan schiers"
wrote:

Necessity being the mother of invention, bit me. Last weekend was CQWW CW
on
160m. I stumbled on it and had no 160m antenna. I have a terrific
performer
for 80m, an inverted L with 33, 60' radials stapled on the ground. I also
have a Carolina Windom 80 at 42' fed with perhaps 100' of RG8x.

Since it was a cw contest, I figured, brute force stuff with my tuner.
Very
interesting results.

I tried the 80m inverted L, feeding just the center conductor, and also
tying the shield and center conductor together ...both cases feeding it as
an end fed wire.

Hi Hasan,

You tied the shield and center conductor together - isn't that a short
circuit for the inverted L?

I got no band noise and very poor signals, but what the

Sounds like a short.

heck, I worked 10 or 15 stations who were running S7 or better in spite of
things.

Could they have been much better?

I could tell I wasn't being heard very well. (I was also running
about 500w output).

Still sounds like a short.

Then I tried the same trick with the CW-80. I fed the center conductor
only...band noise jumped up to S-3, signals were amazingly loud, and I
started working everyone I could hear...first call.

Sounds like a cleared short.

I'm at a loss to explain why it would seem to work so well as a DX antenna
for 160m. Pleased, but surprised. Any theories?

One theory is you could have done a whole lot better - but that is
pure speculation. Another theory is you could have done a whole lot
worse - that doesn't need to be proven because we can all achieve
that.

Am I somehow shunt/gamma feeding my tower?

Could be. Could be so lossy as to defy SWR too.

I also had no tuner arcing, no rf in the shack, no RFI in the hi-fi,
....zippo...all the RF appears to go where I would like it to, but I have
NO
idea why. I prefer to understand things and not just rejoice in my dumb
luck. Ideas?

For one, I've seen a number of posts recently proclaim the
accomplishments of DX, Low Angle antennas. The two are not
necessarily tied at the hip. It is all predicated on the bank shot
against the ionosphere, and a low angle could as easily end up in the
drink as it could in Lower Slobovia. And Versa Vice, a high angle
(call it 30 degrees) could as easily hit Ulan Bator as it could drill
into Pike's Peak.

True, a high angle is more susceptible to multi-hop losses, unless it
is bouncing over the Pacific on the first two caroms. Without a valid
propagation model tied to the radiation distribution characteristics,
calling an antenna a low Angle, DX performer is a mighty flight of the
imagination.

Short answer: a propagation modeler tracking real time results will
answer more questions than attaching claims to simple monopoles or
dipoles.

I've used WinCAP with a highly distorted antenna response curves to
probe launch angles. WinCAP comes with sample antennas, like the
common quarter wave vertical. I've edited that file such that output
at all elevation angles, except one, are severely reduced. Basically
a one degree height elevation lobe set at one particular angle (for
the sake of argument, a 5 degree launch angle, ±½ degree). When it
reaches Europe, the footprint floods France.

Now, we know that such an antenna is nigh on impossible to build for
HF, and the common vertical is going to launch very useful power over
a far greater span of angles. The upshot of this is that instead of
that ±½ degree, we take the typical ±15 degrees around a typical
launch angle of 20 degrees, and you cover a lot of ground at the other
end * IFF * the Ionosphere will support them. And just as much power
will probably hit France even though we've quadrupled that "low"
launch angle FROM 5 degree launch angle, ±½ degree TO 20 degree launch
angle ±15 degrees.

73's
Richard Clark, KB7QHC