Good comments, Jim (below).
However, it seems to me the SteppIR approach probably requires as extensive
a radial field as any other multiband vertical, and that's most of the work
for many of us (including me). If I'm spending a few weekends laying
radials in such a way they won't be tripped over, cut by the gardener, etc,
at that point I may as well install a multi-band linear-loaded (or
equivalent) vertical to cover several bands instantly, without the "wait" or
complexity of a motor driven radiator.
But, that's just me...
WB2WIK/6
> -----Original Message-----
> From: Jim Shaw [SMTP:Jim@ShawResources.com]
> Sent: Monday, October 07, 2002 11:17 AM
> To: Steve Katz
> Subject: RE: [Towertalk] GAO Challenger DX
>
> Steve
> Perhaps to test your statement "if I had to choose just ONE good 40m
> system
> to
> stick with forever, I'd use a full-sized vertical", SteppIR introduced a
> full size 1/4 WL (33 feet) 40M vertical that also mechanically shortens
> itself to be full size on 30 - 10 meters. Unlike Force12 vertical
> dipoles,
> the SteppIR vertical requires radials but appears to be a good choice for
> multiband capability especially when compared to others using traps,
> capacity hats and other approaches to achieve multiband performance. The
> SteppIR vertical appeals to me due to its simplicity: It has just a single
> radiating element (but it probably requires more geography due to the use
> of
> radials).
>
> http://www.steppir.com/
>
> Now I'm torn between getting a couple of Force12 vertical dipoles (to
> cover
> 40 & 20-10M) or taking the SteppIR single 'vertical' plunge (which will
> provide me 30M coverage as well).
>
> 73 de Jim WA6PX
> JGShaw@Alumni.HAAS.org
>
> -----Original Message-----
> From: Steve Katz [mailto:stevek@jmr.com]
> Sent: Monday, October 07, 2002 10:37 AM
> To: 'Jim@shawresources.com'; TOWERTALK@contesting.com
> Subject: RE: [Towertalk] GAO Challenger DX
>
>
> Interesting comments, Jim.
>
> I don't have a 40m beam, myself, but we do at the contest station (K2XR)
> and
> always maintain some vertical antennas to supplement the beam.
>
> The 2L 40 at 90' works well; however, using a GAP Voyager (ground-mounted,
> obviously) or wire slopers off the 140' tower at the site are great
> "go-to"
> antennas that can easily outperform the 2L beam on occasion, depending on
> propagation and path. To use just the beam, always, would be silly. I
> find
> myself frequently switching to the Voyager or a sloper, to see which works
> best for a given DX contact, and use that one to make the call.
>
> Based on my various experiences in winter-months DX contesting from
> stations
> having a mix of antennas, if I had to choose just ONE good 40m system to
> stick with forever, I'd use a full-sized vertical like the Voyager for
> transmitting, and a couple of Beverages, or a small rotary loop, for
> receiving, most of the time. Only problem with the vertical appears to be
> that DX signals are all "S9+" and so is the noise....
>
> WB2WIK/6
>
> "If everything seems under control, you're just not going fast enough." -
> Mario Andretti
>
> > -----Original Message-----
> > From: Jim Shaw [SMTP:Jim@shawresources.com]
> > Sent: Monday, October 07, 2002 10:08 AM
> > To: TOWERTALK@contesting.com
> > Subject: RE: [Towertalk] GAO Challenger DX
> >
> >
> > In general, I agree that the big variable at low heights (less than 1/2
> > WL)
> > is the ground. Always thought low HF horizontal dipoles are DX
> > problematic,
> > particularly on the low bands.
> >
> > Its not clear to me if you are restricting your points to traditional
> 1/4
> > WL
> > verticals with radials, or if you intended the comments to apply to all
> > verticals including 'vertical dipoles'.
> >
> > I have been real interested in the FORCE12 move into 'vertical dipoles'
> of
> > one flavor or another.
> >
> > (See http://force12inc.com/sigmainfo-005.htm)
> >
> > They managed to get a positive QST review (OCT 2002) on their 'stealth'
> > Sigma 5 (9 ft or so high radiator on 20-10M). But they have several
> > 'fuller
> > size' models that they claim are 'DX-pedition proven'. And, although it
> > may
> > be marketing hype (aimed at GAP?), they claim very high efficiency for
> > their
> > vertical dipoles even when mounted just above the ground! Their use of
> > 'capacity hats' to shorten their vertical dipoles seems quite practical
> to
> > me as it avoids the issue of traps.
> >
> > A consideration in favor of vertical vs horizontal dipoles for DX (e.g,
> on
> > 80M where a 1/2 WL 80M dipole is 140 ft) is that dipoles must be
> rotatable
> > to achieve omni directional coverage. Or you may need two or three to
> > cover
> > all directions. Even with efficient shortening, they can be
> > geographically
> > problematic as well as difficult to get high enough. But, for those
> able
> > to
> > use 'brute force', these are not issues.
> >
> > To me, each has pros and cons and circumstances will tend to result in
> > choosing one over the other. I try to know the strengths and weaknesses
> > of
> > each so I can use the best for the situation.
> >
> > 73 de Jim WA6PX
> > JGShaw@Alumni.HAAS.org
> >
> > -----Original Message-----
> > From: towertalk-admin@contesting.com
> > [mailto:towertalk-admin@contesting.com]On Behalf Of n4kg@juno.com
> > Sent: Monday, October 07, 2002 6:23 AM
> > To: TOWERTALK@contesting.com
> > Subject: Re: [Towertalk] GAO Challenger DX
> >
> >
> > Ground Reflections from Horizontally Polarized antennas are
> > very efficient, suffering only 1 to 2 dB loss regardless of how
> > poor the conductivity of the ground.
> >
> > Ground Reflections from Vertically Polarized antennas are
> > HIGHLY dependent on the ground conductivity and are typically
> > much higher than for horizontally polarized antennas unless the
> > reflections are over Salt Water.
> >
> > On the Low Bands, verticals are often better than (low) dipoles
> > for DX where a 1/2 WL high 80M dipole needs to be 140 ft up!
> >
> > Tom N4KG
> >
> >
> > _______________________________________________
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