The SKELTON CONE antenna came to my attention a few years ago through
                        a flyer handed to me by a fellow ham.( TEXT HERE ) It seemed to be good idea at
                        the time, but after building and using one of these things, and listening to others, like
                        me, who seemed to have less than desirable results, I have come to some different
                        conclusions. After researching and reading the thoughts of others, the cone may
                        not be all it is built up to be.

                        The "Cone" is one of the basic HF doublet wire antennas, fed with a balanced line.
                        Most of the printed material I have seen on this antenna calls for 4 wires 51 feet
                        long  fed with 450 ohm ladder line to an antenna tuner. The wires are pared, two for
                        each side of the dipole, spread about 38 feet apart on each leg. This supposed to
                        make the antenna "broad banded." This always seemed strange to me, as the
                        antenna is supposed to work on all HF bands to start with.
                        ( The original plans I saw for this antenna said one could use 300 ohm tv type feed
                        line, but I have NEVER heard of anyone have even slightly successful results with
                        this feed line. ) As I said before, most people use 450 ohm line, but 600 ohm line
                       would have even less loss, adding to the total efficiency of the antenna.
                        The antenna has been likened to a G5RV with 2 extra wires. It is usually erected as
                        an inverted vee and herein lies what I think is the main problem even if the feed
                        point  is kept at 38 feet and the ends at 18 feet the included angle is about
                      130 degrees and that is probably enough to raise the main lobes to an angle that is
                       too high, along with reducing the strength of the signal.

                      There are some copied models included here, please excuse the quality.
                       Just remember that the solid lines represent a flat top configuration, and the
                      dotted lines  represent an inverted vee.  Plots 1 and 3 are for G5RV - type
                      antennas in both flat top and inverted vee installations, while plot 2 shows the
                      difference between a G5RV and a simple dipole, both on 20M.
                       In G5RV configuration, you  will be able to see that as the frequency increases,
                       the main lobes take off at higher angles in the vee configuration until most of the
                       signal is radiated almost straight up on higher frequencies. Again, plot 3 is for
                       20M, and the effect is increased as the frequency rises.

                        As I have read, a G5RV was not designed to be an "ALL-BAND" antenna. G5RV
                        designed it to be an antenna with gain on 20 meters. The fact that it works on the
                        other bands is incidental. Also, the G5RV was not intended to be installed in a
                        configuration other than a flat top. With a big enough tuner, it can be made to show
                        a low SWR in any configuration, but this more a function of the tuner's ability to
                        force current into the feed line rather than the antenna's resonance at any certain
                        frequency. Still, the major problem will be with the radiation patterns this antenna
                        displays when it is installed as an inverted vee.

                        At 1 1/2 wave lengths on 20 meters, it does have gain, but when the ends are
                        dropped down into a vee configuration the lobes change shape and the angle of
                        radiation changes in the direction of lost efficiency. On the bands above 20 meters
                        the lobes of radiation are shaped more like those of a long wire than a dipole, and
                        when this antenna is erected as an inverted vee, the pattern worsens and the gain
                        diminishes as the frequency increases.

                        I have had moderate success on 80 and 40 meters with the Skelton Cone, but I
                        usually  go to my Butternut vertical on the higher bands, although I have worked a
                        few JAs and a lot of US stations on 17 meters off the cone. I would think that the
                        antenna behaves more like a 1/2 wave length dipole or truncated dipole on the 40
                        and 80 meter bands, due to it's electrical length on these bands. From what
                        information I have found, a half wave dipole looses only a little gain when installed
                        as a vee, and will actually pick up a little over a horizontal dipole in the end fire
                        patterns.
 

                        Here are the basic FLAT TOP band patterns for a G5RV. Use your browser's
                        BACK button to return to this page.

                                    Click on the band you wish to see the pattern for.

                                80M    40M    30M    20M    17M    15M    12M    10M

                              ( The above patterns are links from Cecil Moore's web pages. )

                        Gain figures alone will show that the Skelton Cone is less efficient than the same
                        basic antenna installed as a flattop, as shown in the chart below.

                          Gain vrs Frequency for a 151 foot Dipole over average ground, for
                                              both horizontal and inverted vee configurations:
 
                        Horizontal and Inverted Vee, with the vee angles at 90 degree between arms.

                        As you can see, the gain falls rapidly as the frequency increases. Also note, the gain
                        figures are in dBi, not dBd. By the time one reaches 14 mhz, the gain is less than
                        that of a dipole.
 
 

                        In the ARRL Antenna Compendium Volume 4, VE2CV and VE3KLO have an
                        excellent article, explaining in detail, the ideas expressed above.
 

                        If you would like to see the results of some intense research and computer
                        modeling, please visit Cecil Moore's web page by clicking here.

                        Another area of concern is that of the type of antenna tuner used. Most of the
                        commercial antenna tuners available today are of the unbalanced type, designed for
                        50 ohm coax. To feed a balanced line, they usually employ a 4:1 current balun to
                        force feed the antenna system. There are points where the mismatch is so great that
                        the  balun can actually be destroyed by the high voltages encountered.
 

                        A really great  piece of software to calculate the impedance, resistance, and
                        reactance of both the antenna and feed line, along with the line loss, and the
                        voltages and currents an antenna tuner will have to contend with is available
                        under the name of "Doublet.exe", and it can be downloaded by clicking here.
                        I suggest you try it. It was written by R.J. Edwards, G4FGQ, and is very easy
                        to use.
 

                        What is  needed  for an antenna of this type is a really good balanced tuner. To my
                        knowledge, there are none available, or I would have one. AG6K has some really
                        nifty plans for a home brew balanced antenna tuner and I have included a link to his
                        page by clicking on his call sign. His tuner is one of my next projects.
 

                        In short, if one is inclined to use a Skelton Cone type antenna, he/she should be
                        aware that while you may be able to get a good match with an antenna tuner, the
                        radiation  patters on the higher bands will not have good efficiency and most of your
                        signal will be directed in non useful directions. The best configuration for an ALL
                        BAND wire antenna is that of a Flat Top.

                        I am sure that this antenna, like the G5RV, can generate a huge amount of
                        controversy. It is amazing to me that so much time and ink has been spent on
                        discussions and arguments about the G5RV when there are more efficient antennas
                        for the bands this antenna is supposed to work on. The lure of an all band wire
                        antenna has been with us for a long time, and I am sure it will remain for some time
                        to come. It is hard to pass up the idea of one wire covering all the HF bands.
 

                              Some of the conclusions from the research by VE2CV and VE3KLO

                        Radiation patterns:

                        Dipoles are often not installed in a horizontal straight line. Half wave dipoles are
                        tolerant of bending, sloping or drooping to fit a particular antenna location.
                        However, multi band dipoles don't share this tolerance with their single band
                        brethren.

                        The azimuthal radiation pattern of a G5RV type antenna is similar to the radiation
                        pattern of a half wave dipole, but the broadside directivity begins to break down
                        into secondary lobes when the dipole arm length is  5/8 of a wavelength.
                        ( dipole length >1.25 wave length ) For a 102 foot dipole this corresponds to
                        frequencies > 10 mHz. While it will possible to get a match with the proper antenna
                        tuner of these higher frequencies, the multi lobed nature of the radiation pattern
                        means  less of the signal will be directed in the desired direction.

                        A horizontal G5RV type antenna installed at a height of 55 feet will show a gain of 6
                        dBi and a launch angle of 90 degrees at 3.75 mHz.  As the frequency increases the
                        directive gain increases, reaching a maximum just above the 30 meter band, where
                        the antenna is a wave length long. The azimuthal pattern is multi lobed at 14.15 mhz,
                        where the dipole is 1.5 wavelengths long. The elevation angle for maximum gain
                        continuously from 90 degrees at 3.75 mHz to 7.5 degrees at 29 mHz. When the
                        azimuthal pattern becomes multi lobed > 14 mHz, the launch angle for all lobes at a
                        particular frequencies are about the same.

                        The drooping dipole configuration presents particular problems. With the same
                        installed height of 55 feet and the arms at an included angle of 90 degrees, the
                        radiation  patterns are quite different from a horizontal dipole, and the gain figures
                        are much less. (See table)  The reduction in gain is of a particular concern at 14
                        mHz. The standing wave of current on a 1/2 wave dipole is maximum at the center
                        and zero at the ends, so the current is at a maximum at the apex height. Drooping the
                        arms has a minimal effect on gain and pattern. However, when the length is greater
                        than 1/2 wavelength, the points of maximum current are displaced from the center.
                        Therefore, the points of maximum current occur at a lower height when the arms of
                        the dipole are dropped. When the dipole is horizontal, the take off angle decreases
                        continuously as the frequency increases, because the electrical height of the dipole
                        increases in frequency. When the pattern becomes multi lobed the take off angle is
                        the same for all the lobes in the azimuthal plane. This NOT the case of the drooping
                        dipole, and the differences in take off angles between the major and minor lobes
                        increases with an increase in angle of the dipole arms. Things get so bad on some
                        frequencies, due to electrical height of the dipole, that the major lobes take off at
                        nearly vertical angles and the minor lobes are at only moderately low angles so
                        much if not most of the radiated  power goes straight up and is wasted.

                        In detailed studies, inverted vees at angles of 100 and 127 degrees were analyzed,
                        and  the radiation patterns for the antennas at 100 degrees were closer to the vees
                        at 90 degrees, and the antennas at 127 degrees displayed radiation patterns that
                        were closer to the antennas that were installed as flat tops. It is clear that G5RV
                        type antennas should be installed as flat or as nearly flat as possible.