What are some of the advantages and disadvantages of using a vertical antenna on high frequency? Are there any better antenna types that I should use?

The primary advantages of vertical antennas are that they are omnidirectional, and with an appropriate ground plane (radials) yield a low radiation angle; this reduces the number of "hops" that HF signals must make to reach their destination. Ignoring the ground plane, which might be radial wires or metallic screening buried just under the surface, vertical antennas don't take up much space.

The primary disadvantages of vertical antennas are that they are vertically polarized, which makes them more sensitive to man-made noise when used for reception as compared to horizontally-polarized antennas like a dipole, and that they require a good ground plane to be effective when transmitting.

Vertical antennas for the lower bands require a significant mechanical support; for 80m, for example, a quarter-wavelength vertical antenna would be 66' tall. Verticals can be made shorter with top-loading or various tuning schemes, but at the cost of lowered efficiency -- meaning less of the transmitted signal is effectively radiated.

  • Low-band (160m-80m-40m) vertical antennas are often shortened using coils or top-loading, which also brings the disadvantage of making them quite sharply tuned and narrowband. For example, my Bencher HF6V 6-band vertical is only good for some 60 KHz on 3.5 MHz, so I get to choose if I want to work CW, digital, or some subset of the SSB band. Retuning requires a trip to the roof. Shortened horizontal antennas have the same property, but it's easier to hang a 40-meter wire horizontally than to make it stand upright. – oh7lzb Oct 23 '13 at 6:59

One advantage of a vertical antenna (not yet mentioned) is that you can hang a vertical wire over a single tree, while a horizontal antenna needs at least two trees. I use my 50 foot high tree for my vertical 80 meter. Yes, it needs 66 feet of wire to tune properly, but I simply bend the wire over the top and then down. Most of the signal radiates from the lower parts of the vertical antenna, where the most current is.
My method of building the antenna was to throw a string over the tree, and tie the wire to the string and pull up the wire, up and over.

Your Answer

 
discard

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.