Then there is this business of just HOW you DEFINE an Inv El.
Take an antenna that is fed at the ground, against adequate ground, up
67' and out 67' or thereabouts.
Well, that is a 1/4 wave of wire on 160, up 1/8 and out 1/8. Low Z, 25
ohms if you got a good radial system. As good as your radial system.
Behaves like a regular vertical with a minor amount of horizontally
polarized high angle radiation. ALSO...
Feed it at the bottom, moderately hi Z, on 80, 40, 30. Series R losses
in the ground are minimized, and this configuration will forgive some
fairly crappy ground systems on 80,40,30.
On 80 meters, 1/4 wave up and 1/4 wave out, this antenna has a
hemispherical pattern, decent for BOTH DX and local, especially if
it's what you can put up. Current max is around the bend in the wire.
On 40 meters, 1/2 wave up and 1/2 wave out, it acts like the
horizontal part is a dipole, with a single wire feedline/transformer
up to one end of the horizontal. The vertically polarized signal is
cancelled out (non-intuitive, but check it out). Has same pattern as
dipole at 66 feet, pretty good antenna broadside.
On 30 meters, ~3/4 wave up and 3/4 wave out, it is a decent,
relatively low angle omni directional antenna. Nice bonus.
Particularly with a good ground system for 160 the 67/67 Inv El is a
four band antenna.
You can certainly do better than 1/8 wave up and 1/8 wave out on 80
meters.
But if you were talking about 1/4 wave up and 1/4 wave out on 80, this
is definitely competition for an inv vee with the apex at 67 feet, and
for DX, competition for a dipole at 67 feet. And it's useable on three
other bands.
On 160, 67 up and 67 out is definitely an inverted L
On 80, is 67/67 an inverted L? On 40, on 30?
Still LOOKS like an "L", doesn't it. Or stated otherwise, does making
an L large make it not an L?
Can't say an 80 Inv El was a crappy antenna until you specify which
one you meant.
73 from obfuscation central.
----- Original Message -----
From: "Jim White" <k4oj@tampabay.rr.com>
To: "Barry Kirkwood" <bjk@ihug.co.nz>
Cc: "towertalk submital" <towertalk@contesting.com>
Sent: Tuesday, July 09, 2002 9:42 PM
Subject: Re: [Towertalk] Inv L
> Cool - DX feedback - this is what it is all about guys!
>
> ...are we talking about us stateside chaps and our long haul signal
strength
> to you in ZL, Barry?
>
> ...is this based on your learning what antennas the louder stations
are
> employing when they work you on the lower bands?
>
> This would be great to know - although it used to be a "novice"
level
> question that a vertical would have a lower main lobe than say a
> dipole....verticals for long haul good - compromised/shortened
verticals not
> as good....question becomes will the compromised design be better
than a
> horizontally polarized antenna....
>
> W8JI made an excellent point that this about transmit antennas and
not
> rx'ing - sometimes its astounding to step through the antennas on
your farm
> and realize that heah this antenna for band y is hearing better on
band x
> (at the moment :-)) - sometimes a non resonant antenna with a preamp
will
> sound great - hence the description I like best of the Beverage
antenna -
> works poorly except in one direction where it doesn't work AS bad...
>
> You never know....antenna switching can make for hours of listening
pleasure
> in the Wintertime on the low bands...assuming you do not live in FL
where we
> have better things to do in Winter than listening to that pophiss
scratch
> static
>
> 73,
>
> Jim, K4OJ
>
>
> ----- Original Message -----
> From: "Barry Kirkwood" <bjk@ihug.co.nz>
> To: <genewill@ordata.com>; "Tower Talk" <towertalk@contesting.com>
> Sent: Tuesday, July 09, 2002 7:56 PM
> Subject: [Towertalk] Inv L
>
>
> > Inverted L does very well on 80 and 40 (will eat any all band
vertical on
> > these bands, other things equal).
> > On 40 and 80 it is not too difficult to get full size or top hat
verticals
> > operational hence inv L not as popular.
> > IMHO lots of operators would do better on DX on 80 with an
inverted L than
> > with other popular antennas eg low dipoles.
> > 73
> >
> > end
> > Barry Kirkwood PhD ZL1DD
> > Signal Hill Homestay
> > 66 Cory Road
> > Palm Beach
> > Waiheke Island 1240
> > NEW ZEALAND
> > phone/fax 64-9-372-5161
> > www.waiheke.co.nz/signal.htm
> >
> >
> > _______________________________________________
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