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I've also taken a closer look at my antenna and to my surprise, the PDL quad with its dipole driven element is vastly different then other quads. All other quads feed the signal into one side for vertical polarization and into the bottom (or top) for horizontal polarization.

Something very interesting starts to happen when you drive the quad through a half wave. The feedpoint for the half wave is low impedance but the ends that drive the quad are high impedance. This allows the horizontal dipole to feed the quad at the sides while the radiation currents in the quad are still orientated for horizontal polarization. Just as though it were driven at the bottom without first passing through the half wave section.

Now it makes sense that the radiation currents of the dipole and the quad driven element are reinforcing each other to provide the increased gain we do see with this design. Why was it never taken past 2 elements is a mystery. Perhaps it has to do with patents held on the matching network or Avanti not wanting to create competition for their easy to assemble Moonraker series.

<blockquote data-quote="Shockwave" data-source="post: 374503" data-attributes="member: 10882">I&#039;ve also taken a closer look at my antenna and to my surprise, the PDL quad with its dipole driven element is vastly different then other quads. All other quads feed the signal into one side for vertical polarization and into the bottom (or top) for horizontal polarization. Something very interesting starts to happen when you drive the quad through a half wave. The feedpoint for the half wave is low impedance but the ends that drive the quad are high impedance. This allows the horizontal dipole to feed the quad at the sides while the radiation currents in the quad are still orientated for horizontal polarization. Just as though it were driven at the bottom without first passing through the half wave section.&nbsp;Now it makes sense that the radiation currents of the dipole and the quad driven element are reinforcing each other to provide the increased gain we do see with this design. Why was it never taken past 2 elements is a mystery. Perhaps it has to do with patents held on the matching network or Avanti not wanting to create competition for their easy to assemble Moonraker series.</blockquote>

[QUOTE="Shockwave, post: 374503, member: 10882"] I've also taken a closer look at my antenna and to my surprise, the PDL quad with its dipole driven element is vastly different then other quads. All other quads feed the signal into one side for vertical polarization and into the bottom (or top) for horizontal polarization. Something very interesting starts to happen when you drive the quad through a half wave. The feedpoint for the half wave is low impedance but the ends that drive the quad are high impedance. This allows the horizontal dipole to feed the quad at the sides while the radiation currents in the quad are still orientated for horizontal polarization. Just as though it were driven at the bottom without first passing through the half wave section. Now it makes sense that the radiation currents of the dipole and the quad driven element are reinforcing each other to provide the increased gain we do see with this design. Why was it never taken past 2 elements is a mystery. Perhaps it has to do with patents held on the matching network or Avanti not wanting to create competition for their easy to assemble Moonraker series. [/QUOTE]

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