Hi Don: 

            Others may better explain the Alpha Delta DXCC multiband dipole
antenna better than I, but here’s my response to your questions.  

            The DXCC model has 3 dipole insulated wire elements of different
lengths coming out  of the Alpha Delta center insulator.  On each side of
the center insulator emerge 3 wires for the various bands covered by this
antenna.  On each side there is one 41 foot length wire that covers the 80
meter, and 40 meter bands.  The 40 meter length of this wire is utilized for
15 meters, based on a 1/3 wavelength harmonic.  Aditionally, there is one 16
and ½ foot wire coming out of each side of the center insulator for the 20
meter band.  There is also one 8 foot length of wire coming out from each
side of the center insulator to cover the 10 meter band.  The 10 meter and
20 meter dipole wires are laced through a mesh like “grid” for lateral
support, this mesh also connected to the center insulator.  There is,
therefore, no requirement for the ends of the 10 meter and 20 meter wire
elements to be supported or tied to a tree or a pole, etc., because they are
supported in space by the mesh grid.  The two 41 foot wire dipole lengths
are laced through the upper edge of the mesh grid, and serve as the lateral
support for the  mesh grid and the 10 and 20 meter wire elements that
achieve lateral support by being laced through the mesh grid.  Thus, the
placement of the 41 foot wire elements of the dipole serve to provide a
similar alignment or direction of the 10 and 20 meter dipole wires as they
are in parallel, directly below the longer 41 foot wires extending away from
the center insulator.  

            My DXCC arrangement works very well on 40 meters and 20 meters,
not requiring a tuner.  10 meters may or may not require the use of a tuner,
depending upon frequency chosen.  Same  goes for 15 meters.  This antenna
(mine, anyway) requires the use of a tuner for 12 and 17 meters...I don’t
believe that it was designed for these bands...  But on 75/80 meters, I
absolutely am required to use an external tuner, and the fine tuning is
critical to achieve low s w r for me on this band.  Even tiny little
adjustments of the external tuner on a given frequency in the 75 meter band
causes s w r to jump.  Others users of this antenna may not have this
experience on 75/80 meters.  However, one of the 41 foot wire elements of my
dipole terminates within about 12 feet of the metal roof on my house, which
may be throwing a fly into the ointment.  I do get good  signal reports on
75/80 meters as well as 40  and 20 meters, the bands that I most frequent.


            I hope that description helps to answer your questions.  This
missive isn’t necessarily sent to steer you in one particular direction, but
rather to describe the structure of the dipole and a bit of my personal
experience with it.  

                                                            Regards, 

                                                                        Dave
Weigel   KD4JEZ