20 dB implies that the ground system loss is 10X the inverted-L radiation
resistance.
This would result in an input resistance of 250 ohms and a minimum VSWR if
5:1.
I don't think that is what the real deal will deliver, do you?
Dave WX7G
On Dec 12, 2012 12:54 PM, "Guy Olinger K2AV" <olinger@bellsouth.net> wrote:
> With the following caveat: The very sparse and short buried radial systems
> he is showing are FAR more lossy in practice than shown in his gain tables.
> Four twenty foot buried radials beneath a 1/4 wave L on 160, could place
> you down 20 dB. You really can't do that as your 160 meter counter poise
> and expect decent results. You can end feed the same wire on 80/40/30
> meters (full wave worth of wire in the L on 80m) with four buried 20 foot
> radials and it will be an excellent antenna. This is due to the high Z
> feed at the ground with current max AWAY from the feed point.
>
> A quarter wave L on 160 MUST deal with the counterpoise loss issues, one
> way or another.
>
> 73, Guy
>
> On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee <Ashton.R.Lee@hotmail.com
> >wrote:
>
> > This wonderful article written by L.B.Cebic W4RNL sure can make you a
> > believer in a simple wire inverted L. It is the last antenna discussed.
> > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf
> >
> > A $3 wire pulled up into a tree will beat just about any commercial
> > antenna… because it is longer. So on low bands it has increased band
> width
> > and efficiency, and on higher bands it has gain. Yes, I know , some of
> that
> > high band gain is horizontally polarized, but that's not all bad. Just
> get
> > the vertical portion 33 feet or so and you'll be happy as Larry. The
> > article shows that an extensive radial field may not be necessary.
> >
> > And a wire is a lot less visible than a big hunk of aluminum. Without
> > trees, just top load a 43 foot (or possibly even shorter) vertical. The
> top
> > loading could be a T just as easily as an L. People can argue that one
> all
> > day.
> >
> >
> >
> >
> > On Dec 12, 2012, at 11:30 AM, k6xt <k6xt@arrl.net> wrote:
> >
> > > My first antenna, still in use, on moving to CO is a GAP Titan,
> > advertised to load up 80 thru 10 including WARC bands. The Titan is a bit
> > shorter than Voyager, 28 feet or something like it. The advertising is
> > correct, it loads up 180 thru 10.
> > >
> > > But wait. Is it effective on all those bands? No.
> > >
> > > On 80 its a dummy load. On 40 it works extremely well after I added a
> > one foot extension to the bottom wire that encircles the antenna. In some
> > cases it is the equal of my shorty HyGain 40 at 70 ft - which probably
> says
> > more about the HyGain than the GAP. For the rest its better on the
> > traditional bands than the WARC bands. It worked a lot of DX for me for
> the
> > couple years it was my only antenna.
> > >
> > > Carrying my experience to the few feet taller Voyager, and from what
> > I've been told by Voyager users, the ant will meet its spec which is to
> > load up on the low bands. Expectation wise I'd expect it to be like the
> > Titan. It loads up but is otherwise a dummy load. Maybe with a batch of
> > radials it could be made to work as well as any other extremely short
> > vertical or GP.
> > >
> > > Not to say there's anything wrong with GAP. My brother had up an R7
> > which he rated about like the GAP on bands both cover. Those multiband
> > halfwave short verticals work but you get what you pay for.
> > >
> > > 73 Art K6XT~~
> > > Success is going from failure to failure without a loss of enthusiasm.
> > > ARRL, GMCC, CW OPS, NAQCC
> > > ARRL TA
> > >
> > > On 12/12/2012 10:00 AM, topband-request@contesting.com wrote:
> > >> With the prospect of downsizing and moving into senior housing in the
> > future
> > >> I am starting to look at vertical antennas that will allow me to
> > continue
> > >> this wonderful hobby.? I have heard "some" good things about the GAP
> > series
> > >> of antennas but the company says they do not need radials on most of
> > them
> > >> and that worries me.? Over the years I have become very skeptical
> about
> > >> claims and the other BS put out by most companies ( maybe it is a
> > function
> > >> of age I dunno) so I wonder if these antennas really work.? The two
> > antennas
> > >> that I am interested are the Voyager DX for 160/80/40? and the Eagle
> DX
> > for
> > >> the rest of the bands.
> > >>
> > >> So my question is.... does anyone have actual experience with these
> > antennas
> > >> (especially the voyager) as compared to other antennas for a specific
> > >> frequency.? Now guys .. I know you cant really compare a 6 element
> beam
> > to a
> > >> vertical of this kind but I am talking about a comparison that is
> > >> realistic.. like how does it hear, tune, match & get out compared to
> > >> something like another vertical or a dipole up some reasonable
> distance.
> > >>
> > >> I sure hope this has not opend another can of worms.. some how I seem
> > to do
> > >> that .. private emails are ok..especially it the topic gets out of
> hand
> > and
> > >> we get a large volume of comments (Tree please dont shoot me before
> > >> Christmas my wife will miss me.)
> > >
> > > _______________________________________________
> > > Topband reflector - topband@contesting.com
> > >
> >
> > _______________________________________________
> > Topband reflector - topband@contesting.com
> >
> _______________________________________________
> Topband reflector - topband@contesting.com
>
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