[Antennas] Multiband Vertical Versus Multiband Dipole (HF)

2002年10月28日 11:56:04 -0700

A good matching system will allow you to use almost anything as an
antenna. I currently have approximately 330 Ft. of THHN #12 wire wrapped
around the out side roof line of my house under the eave. It's almost
invisible. I feed the wire directly to the back of an old Johnson
"Kill-a-watt" Matchbox. I have no trouble talking to all states, Eastern
Europe, Russia, South America, What-Have-You. I also have a Folded
Dipole cut for 80 Mtr. fed with open Ladder-line and a regular dipole fed
with RG8U coax. Neither of which show much improvement over the 330 ft.
longwire. 
If you can't put up a tower and beam, you don't have to be exotic, you
just have to make sure that your system can be matched to whatever you
are using for an antenna. It's harder today with the solid state rigs
that will not accept an SWR of 2:1. "Back in the old days" we used to
load screen doors and gutters with the old tube rigs and Matchboxes.
73's de Jerry, K�EJF
On 2002年10月28日 08:01:57 -0600 "Linden, Mike (BRC-Hes)"
<[email protected]> writes:
> A lot of folks still say that a vertical radiates equally poorly in 
> all
> directions (they should only be used if you don't have space for a 
> "real"
> antenna). After researching it a bit, it is my contention that such
> verticals don't have an adequate ground system or are being used in 
> areas
> with poor ground conductivity. My goal is to have some sort of 
> support for
> most of the bands between 10 and 80 meters.
>> I'm currently running a homebrew multiband coaxial trap dipole in 
> my attic
> at about 25 feet. However, I'm thinking ahead to when I have enough 
> time and
> when I can convince my housing association to let me install some 
> outdoor
> antennas. My two HF options would be a multiband vertical (I like 
> the
> Butternut HF9V) or a multiband dipole (I've seen some designs that 
> only add
> significant loading on the lowest bands).
>> Personally, from an aesthetic point of view, I like the vertical. 
> I would
> be able to install it more than 30 feet from my 2-story vinyl sided 
> house
> and would have enough room for 30 foot radials in all directions. 
> The
> antenna would be ground mounted. Ground conductivity in my area (far 
> west
> Chicago suburbs) is quite good. My primary concern with the vertical 
> would
> be increased noise due to vertical polarization. Any comments on 
> how
> manageable the increased noise is and how much worse it is than a 
> dipole?
> Based on my research, the primary benefit of a vertical is the low 
> angle of
> radiation that results when used with a good ground system.
>> The dipole installation would not be as aesthetically pleasing as 
> the
> vertical (at least from my perspective -- hi!). Due to the lack of 
> older
> trees in my new subdivision and the layout of my lot, the dipole 
> would have
> to run from my house straight into the back yard such that the feed 
> point
> would drop in my back yard 30 or 40 feed from my house. Probably the 
> best
> height I would be able to manage would be about 30 feet above ground 
> --
> perhaps a bit lower at the far end -- I would also need to come up 
> with some
> sort of middle support. Based in my research, the benefit of the 
> dipole
> would be lower cost (about 100ドル) and lower noise level. However, at 
> 30 feet,
> the angle of radiation would not be very good for DX.
>> I'd appreciate feedback from folks who have had the chance to 
> compare the
> performance of multiband verticals with multiband dipoles.
>> Thanks, Michael N9BDF
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E. Jerold (Jerry) Forwood