Best HF Vertical Antennas

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Tom Rauch:
The ground system is 95% of the performance of a vertical. Even traps have negligible loss.

The exception to this are the weird designs that use odd things like linear loading, resistor loading, and coax stubs.

GAP verticals on low bands are terrible, as are the Sommer 25 verticals that use resistor loads. So are most "no radial" verticals. Stay with traditional designs using traps or air-insulated decoupling stubs.

73 Tom  

Ron Wray:
Not all verticals are monopoles- there's also the vertical doublet which can be constructed of either (hung) wire or (guyed) aluminum , and can be cut for multiband or monoband operations.  Vertical doublets do NOT require grounds / radials / counterpoises.  On the other hand, feedline installation often requires compromise (since it's usually difficult to bring the feedline away from the center of the antenna at 90 degrees).  Due to the height above ground, many suburban QTHs are not suitable for the installation of these antennas.
I've been using 32' & 44' vertical doublets for many years- they are good multiband performers & easy to construct.  See also http://www.cebik.com/gup/gup39.html for W4RNL's excellent analysis on the 44' vertical doublet.

Tom Rauch:
by WB5HZE on September 26, 2004 Mail this to a friend!
Not all verticals are monopoles- there's also the vertical doublet which can be constructed of either (hung) wire or (guyed) aluminum , and can be cut for multiband or monoband operations.
I've been using 32' & 44' vertical doublets for many years- they are good multiband performers & easy to construct. See also http://www.cebik.com/gup/gup39.html for W4RNL's excellent analysis on the 44' vertical doublet.>>>

They certainly work, but may not be as efficient as we think.

 It's easy to make an efficient short antenna if you ignore matching losses and feedline losses!!!
As an example Cebik's analysis fails to include feedline losses, which for 40 meters (with the 44ft dipole) can be about 2dB.

I notice his model shows -.41dBi on 7MHz for a 44ft vertical dipole (which is by itself down about 7dB or so from a horizontal dipole), but neglects feedline losses and problems caused by the feedline (affecting pattern).

If you assume the feedline does not add pattern distortion or radiation, you have to add another 2dB loss on 40 meters for 75 feet of brand new dry 450 ohm line. Get the line wet or let it age, or have common mode currents and the problem is worse.

The result is actually 10dB weaker (or even worse) than a dipole fed with coax at 44ft height!

Since even a very modest ground system would provide 50% efficiency, it makes little sense to go with a short (44ft in this example) vertical dipole when a 30ft or shorter vertical with a small ground system can have more efficiency.

For an analysis of feedline loss in a short dipole see:

http://www.w8ji.com/short_dipoles_and_problems.htm

If you are going to use a truncated antenna, match at the antenna.

73 Tom  
       

Lee A Crocker:
When I started in ham radio QST always touted the "Gotham Vertical".  I never could afford one, but the add claimed you could work the world.

73

W9OY

Ron Wray:
Tom, you make some good points with which I concur 100% . . . especially that matching is best done at the feedpoint.  But the loss projections (intentionally or not) seem to be presented as absolute worse case- AND it certainly is comparing apples with oranges to place the gain of a (full size) coax-fed monoband (horizontal) dipole against that of a (short) twinlead-fed multiband (vertical) doublet.  It would be only fair to compare instead a monoband (or multiband) vertical doublet against a monoband (or multiband) vertical groundplane at the same top height, both similarly fed.

But I grant that you are a very knowledgeable fellow & this certainly isn't the place to argue fine points- the guy just wanted to know what vertical is the best.  And that's a tough call in in this case, since he doesn't provide additional info regarding his objectives & constraints <Multiband operation?  What bands, then?  Small lot? Available supports?  Deed or municipal restrictions?>.  If he was asking what COMMERCIAL vertical antenna is best- well, even that answer is dependent on what he wants to accomplish and what his site conditions might be.

My point was that there exists another type of vertical besides the monopole, one which is suited for some situations & when properly designed and installed works well within its design constraints (just as for any other vertical).

BTW, I presently have a trapped vertical (5BTV) in a ground plane configuration as well as a 44' vertical doublet.  Sometimes one is slightly better, sometimes the other, usually they are about the same (no surprise).  For quite some time I used a 17' ground plane with an SGC tuner at the feedpoint- an arrangement which I liked quite a bit, but unfortunately I never compared it against other verticals.  I've never built <full-sized> 1/4 wave or 5/8 wave monoband verticals with "excellent" grounding systems (being content with what I already had up, & frankly, too lazy/ timid of the XYL to run so many radials)- but these would likely be the overall best performers, especially for the lower bands.  Unless we start talking about vertical arrays, that is . . .

Oddly, no one has brought up the subject of the vertically oriented fan dipole ;~) .

73 . . . Ron WB5HZE

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