[Antennas] Vertical

[Bob Nielsen]

I didn't say it loaded well.  At some frequencies I could load it with
just the autotuner in my TS-570, but at others, I used an external
MFJ-949 tuner.  In all cases I tried I was able to present an adequate
match to the transmitter.  The loss (including added loss due to VSWR)
of ~90 feet of RG-8X probably helped :^)

I also have a MFJ-1793 vertical (1/4 wave on 20 and 40 with
coil/capacity-hat loading for 80) that I plan to put up, although I
don't have space for adequate radials (the ground conductivity here is
much better than when I lived in the Arizona desert).  I expect this
will perform better on 80 than the AV-640, but have no illusions of it
comparing well to a dipole.  I could put up a shortened dipole at a
height of ~20 ft or so, but I suspect the performance would be equally
poor except for NVIS propagation.

73, Bob N7XY

On Thu, Nov 20, 2003 at 01:48:24PM -0800, Alan C. Zack wrote:
> Interesting that the AV-640 will load up on 80 mtrs even though it is
> not advertised to do so.  I wonder if anyone else could comment on
> their experience of having a 10-40 mtr vert load OK on 80.  I don't
> have any luck making a R-7 or R-7000 load on 80.
> I am looking at the DX-77 vert and wonder if anyone has any luck
> loading it up on 80 mtrs.
> All comments are welcome.  And no, I don't have room for a full size
> 80 mtr dipole.
> TIA & 73.
> 
> Bob Nielsen wrote:
> > 
> > On Thu, Nov 20, 2003 at 09:05:59AM -0800, Jim Lindberg wrote:
> > > I am wondering if anyone one the list has had any luck using one of the
> > > better known verticals such as Butternut, Gap, Cushcraft  ect without
> > > radials? I have a tower I can crank up to about 40 feet but no room for
> > > radials. I have a autotuner for my ham radio but I also want to use it
> > > for SWLING.
> > 
> > I have a Hy-Gain AV-640 on a 15 ft. mast with no radials.  It is
> > quite similar to the Cushcraft R-8, but no traps.  There is no magic
> > happening (although it seems to be necessary in ads for Gap, which is
> > why I didn't consider their products), but the performance exceeds my
> > expectations, with contacts in EU, AS and AF on all bands from 40 to
> > 10.  With a tuner, I have made contacts up to 1500 miles on 80 and 160,
> > as well.
> > 
> > Years ago I had a Hy-Gain 14AVQ and wasn't too impressed with it, even
> > with elevated radials.
> > 
> > However, with a 40 foot tower, you would certainly have better
> > performance with a yagi or quad.  The tunability of the SteppIR is
> > particularly suitable for SWLing, WARC bands, etc.
> > 
> > 73,
> > Bob, N7XY
> > - - -
> > 

-- 
Bob Nielsen, N7XY                          n7xy (at) n7xy.net
Bainbridge Island, WA                      http://www.n7xy.net