Horizontial Vs. Vertical Dipole Antenna.

[Anonymous]

Good day everyone, I hope you and yours are well. As the header says, thoughts on HF Vertical Vs. Horizontal Dipole Antennas. Thanks and be well. Mike, Central Mass.

73’s.

KC1NCT.

 

 

 

[Hamilton]

Hello Mike,
<p style=”text-align: left;”>I have a article on a 20m vertical dipole on the club website. As a vertical it has a low elevation pattern (aka takeoff angle) making it great for DX but not for regional QSOs. It is omnidirectional and very quiet.</p>
Since it is a dipole it does not need ground radials like a ground mounted 1/4 wave vertical therefore ground losses are reduced making it a very efficient antenna.

At less than 1/4 wave above ground a horizontal dipole will have a near vertical takeoff angle and will be nearly omnidirectional. It will be better for regional comms but less effective for DX.

As you approach a 1/2 wave above ground the takeoff angle of a horizontal dipole will decrease making it good for DX and it will become more directional.

To your question; If you want to cover your state and a few adjacent states a low horizontal dipole is better than a vertical dipole.

For really long distance DX I prefer the vertical dipole. My high horizontal dipole is a close second but rarely out performs my vertical dipole. Both are next to useless for comms in my state and adjacent states which is a problem during 13 Colonies or the NE QSO party. To fill the gap I added a low (45′ AGL) 80m inverted V.

73

Hamilton K1HMS

[Bob Beatty]

Depends on the height of the horizontal  dipole.  The ideal height above ground is 0.6  wavelengths (per VOA).  As height decreases the takeoff angle increases, which says your propagation will be shorter, and at a high enough angle (critical angle), might pass through the ionosphere entirely.

https://www.voacap.com/antennas/squeezing-decibels-out-of-dipole/#:~:text=The%20optimal%20minimum%20height%20is,of%20height%20over%20the%20ground.

A vertical dipoles work quite well at low heights, with a much lower takeoff angle, which supports longer distance QSOs.

73, Bob, WB4SON

[Jwahar Bammi]

om KC1NCT

I echo what Hamilton wrote about vertical dipole vs. horizontal, especially the points around DX vs NVIS. My reason for this post is to let you know a easy and cheap way to construct a vertical dipole. (see 2 you tube videos below from where I got inspiration)

• Take a 1/2 wavelength of Coax (I used RG 58), + about 16 ft extra
• From the cut end measure 1/4 wavelength
• Strip that 1/4 Wavelength outer conductor and shield, and just leave the inner  conductor with its jacket intact
• Keep the whole coax intact for the next 1/4 wavelength
• At the bottom, wind a ugly balun/common mode choke with the extra length of coax beyond the 1/2 wavelength
• At the end solder a so 239 (female) and seal it with coax seal
• Seal the 1/4 wave point where you stripped the outer jacket and shield so that water does not enter the coax there
• Hang the the whole shebang vertically from a tree with the stripped end on top by the inner conductor
• Feed it at the bottom where you installed the so 239
• For wave length calculation  use 3e+8 * VF / Freq in Hz, where VF is the velocity factor of your coax

This has significant advantages over taking a horizontal dipole and hanging it vertically, the chief advantage is that you are feeding it at the bottom. The middle feed for the turned horizontal dipole is problematic because you have to feed it perpendicular to the vertical, which is near impossible to do in midair. The second is cost: about 48 ft of RG58. Most hams have 50 ft of random coax cable lying around! In the worst case you can make with from cheap 75 ohm TV cable, the impendence will not make any noticeable difference at HF.

For the ugly balun, for different frequencies, I have followed the recommendations in the following article for diameter and number of turns. I make a form out of cut Amazon shopping boxes around a cross of junk wood pieces each of diameter length, crudely nailed together. Once you have the balun wound, tape/wire tie it and pull out the form.
http://www.karinya.net/g3txq/chokes/

Here are 2  You Tube video of the vertical dipoles by VK2PRC and G5TM

I have deployed 15, 17, 20 M versions at various points and am very happy with the outcomes.

73 de k1jbd
bammi

 

 

[Anonymous]

Thanks, I appreciate the comeback, very informative. Take care.

[Anonymous]

Thanks, appreciate the comeback. Be well.

[Anonymous]

Thanks for the information. Be well.

[Author]

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