[Antennas] no radial vertical antennas

[Ron W7MRR]

 Hi Reggie:

   You have hit on a topic that causes a great deal of consternation among readers in this usergroup.  In any case, it is a valid question that you should have the answer to before spending alot of money on an antenna that fails to meet your expectations.

   The antennas hailed as "radialess" verticals are not really verticals at all but are end fed windoms utilizing loading coils and, in some cases, capacity hats to deliver an acceptable SWR over a number of bands.  They go by the name of Cushcraft R-7, R-7000, R-8000, the MFJ 1796 and others.  As a group, they do not perform as well as full size arrangements, but they do deliver a system that will get you on multiple bands, albeit with a less than commanding signal. This is a relative comparison, but one that is supported by the many users reporting to www.eham.com [reviews].  

   My experience with an R-7 that is roof mounted [35 feet off the ground] when compared to an inverted vee at the same height was that the inverted vee was 1.5 to 2.0 "S" units better on both receiving and transmitting on all bands [using a tuner on the inverted vee].

   So to answer your specific question, no I don't believe 1/2 of the RF is going into the ground with these antennas.  It is more likely being turned into heat.  Again, however, if you only have 3 square feet of horizonal space and 12-20 feet of vertical space available for an antenna and want to operate many bands, it may be the antenna of your dreams.  It's just alot of money to pay for an antenna that could be out performed by $10 worth of wire and your built-in transceiver antenna tuner.

   If this discussion invokes the wrath of Kahn as it has in the past, please read the responses closely.  If they speak in terms of working countries, DX, etc., understand that they are not answering your question.  They are defending a less than optimal investment.

   Lastly, if you really want a vertical antenna, you will need to consider the need for a good radial system.  By the time you string and bury the 100+ radials needed for an efficient ground system, you will have spent many times more than what a simple wire antenna would cost and this is even before raise the vertical radiator is raised!

   Good luck and have fun.  

Ron W7MRR


--- On Sun 04/14, Reginald Mackey  wrote:
> I would like to install a vertical antenna and I am confused as how some
> of
> them are advertised to work without radials? Even the 80" radials
> seem to
> short according to typical vertical theory of operation. What is the
> efficiency of these antennas? Can someone shed some light on these
> antennas
> for me? For 3 to 400 dollars I would not want to put 1/2 of my power into
> the ground.
> Thanks in Advance,
> 
>             Reggie
> amateur radio station k6xr
> in southwest Bakersfield
> 
> - - - 
> 
> Your moderator for this list is:
> Larry Wilson KE1HZ antennas-owner@mailman.qth.net
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