I have been wondering why my silly Inverted Vee has been beating my UrbanBeam up 46 feet on 40M this summer. Noise is one issue – the horizontal antenna has been very noisy. The Inverted Vee has a higher take off angle – as does the UrbanBeam on 40M when it is “only” up 46 feet.
I can see that low angle arriving signals would fly under the radar so to speak – and this is where even a single vertical would work better than a horizontal antenna that is 1/2 wl or less. The higher the horizontal antenna, the lower the take off angle.
It does look like adding the 20′ of AB-577 mast will drop the takeoff angle and give significant gain over the vertical or phased DV-40-P phased vertical array. If you have lamented that you can’t DX on 40M because you don’t have a 65′ or more tower – check out the DX Engineering DV-40-P – it can save the bottom of the cycle for you – you will work lots of DX with this system, and maintenance is easy – if you care to deal with radials. I worked 18 ATNO’s at the bottom of Cycle 23 with the DV-40-P, including entities like ZS8M, VU7RG, FT/T and other “very rare” DX (at that time).
Anyway – bottom – line – the four new AB-577 extension tubes – raising the UrbanBeam to 65′ should make all the difference.