UrbanBeam up 65′ vs. 2 Element Yagi up 65′ on 40M

The UrbanBeam right now is actually only up 45′, not the 50′ I thought. Its not a great DX antenna at this height – but it did seem to (usually) match the DX Engineering DV-40-P phased vertical array. I suspect that the DV-40-P had a pretty great low take off angle that beats a low 40M dipole. When I had the DXU-32 up only 50′, it was gang busters, that was the best 40M antenna I have ever had – but trying to get even a “Shorty 40” 2 element 40M yagi up high enough takes some effort. This is where the DV-40-P was a marvel – the bang you got for your buck – and the fact that it was very easy to maintain will always be a great memory.

However, I want what I had in the DXU-32, but only on 40M. Hence all of my interest in a 2 element “shorty 40” yagi.

Getting the UrbanBeam up to 65′ would make a very big difference for 40M (its a folded dipole there). Replacing it with a 2 element 40M yagi would be a major improvement over the UrbanBeam up 65′

The guying for the 4 additional tubes that I will be getting in about 2 weeks. I found the tubes on my nightly 75M Net – so that was a happy accident!

Ben at Ontario Surplus has the miscellaneous parts that I need – so I ordered 4 new clamps and 1 mid level guy ring. I’ll need some dacron guy rope too. Then I will be set. The yagi will be just above the top tube. I will not use a rotator – this way the antenna will stay up easily – it will be about 30 pounds less than the DXU-32 and also have a boom 10′ smaller than the DXU-32.

I don’t know when I’ll swap the antennas – I’m thinking I should keep the UrbanBeam up 65′ until switching to a 40M yagi makes best sense.

But at some point I expect I’ll make the switch.

4 Comments on “UrbanBeam up 65′ vs. 2 Element Yagi up 65′ on 40M

  1. A pal of mine has had almost all the available 40M Yagis on his pole. That includes a shortened M2, Cushcraft, Optibeam (both two and four element versions), a modified Cushcraft W6NL Moxon conversion, and even the monster M2 full sized four element Yagi. I think he may have even tried one of the Mosley antennas. (Although he hasn’t had a JK 40M antenna up there, he does have a two element 80M Yagi by JK.)
    They all had their pluses and minuses.
    He really likes how the Optibeams are built and their customer support.
    He also liked how well the monster M2 performed. Be prepared to use a specialized rotator, though. And a large economy sized support pole.
    Overall, the W6NL antenna performed fairly closely to the two four element Yagis, but not quite. However, he thought the performance was especially good for the size of the antenna.
    My point?
    Perhaps the JK402-Piccolo is a good choice when you don’t have a substantial tower and rotator combination.
    I confess that I’ve never seen one of these Piccolo antennas, so I can’t offer a first person opinion.

    Liked by 1 person

    • The Picolo is the W6NL Dave Lesson Moxon design

      It has no more gain than any other antenna, but has great bandwidth and excellent F/B

      Liked by 1 person

      • I haven’t looked at this recently, but if I recall right, the original W6NL design was larger. I think the elements were closer to 44-46 feet long. Maybe. In any case, the general goodness of the W6NL concept is why I suggested the Piccolo.

        Also, not to be a jerk on the subject, but unless I either modeled the design myself or measured it, I’d be wary of published gain numbers. Coil losses matter, as one example.

        But, in the end, a half dB here or there probably doesn’t matter. The terrain effects are far larger than that. Even HFTA can be misleading in some cases because it uses a ray tracing technique. That’s a very effective approach, but antennas have broader radiation patterns than a ray does. So, to do a thorough job on an analysis you need to simulate over a moderate set of azimuth values and average the results using a weighting factor. Even that doesn’t totally account for rolling terrain and its effect on the total pattern.

        In any case, aside from moving your tower – perhaps to a different town! – or bringing in a bulldozer for a year or two of removing your neighbors’ property, there isn’t much you can do about it all.

        Better to go for a good mechanical design that is more likely to stay up and do so with minimal maintenance.

        Liked by 1 person

      • I will seriously consider it. I just found out the local XM-240 does not have all of the parts, so I will be purchasing something new instead. I will consider the Piccolo.

        I have done a full HFTA evaluation of this QTH – K6TU uses one of my plots as an example on his sight.

        I totally agree on the mechanical design an specs. Some of the published specs are obviously “too good to be true” – but one thing that is critical is that the antenna stay up in different weather conditions. Where I live – weather is as about as benign as any other place I’ve lived. But still – I want the antenna to perform and also stay up

        Like

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