The M2 40M4LLDD

The final Yagi antenna that I plan to soon install on my tower is a M2 40M4LLDD.  The antenna is quite large, but not near as heavy as I expected.  When assisted by another person, we can easily move this antenna around as I prepare for installation.  I hope the performance of the antenna is as impressive as its physical appearance. Overall, I would say the quality of the antenna is good, but there is room for improvement in regard to the instructions contained within the assembly manual, and with some of the hardware items.

First, there is a problem with the turnbuckles supplied to adjust the Phillystran lines that support each of the elements and linear loading lines.  The installation instructions show the element turnbuckles installed with the jam nut facing the center support bracket.  However, the end of the turnbuckle that has the jam nut is a closed loop, so it cannot be installed on the center support as shown.  Installing the turnbuckle in reverse, would allow the turnbuckle to loosen because the Phillystran line is not stiff enough to prevent the turnbuckle from turning.  To fix that issue, I had to also install a second jam nut on the opposite end of the turnbuckle. The nuts are left hand threaded and after checking multiple big box stores without success.  I was lucky enough to find them at one of the local True Value hardware stores.   

Another item that really concerns me is the boom support. M2 supplies a piece of UF rated rope, a mast bracket, and two turnbuckles to support the 42 foot boom.  I can see the rope not lasting very long and failing under stress if there is a significant freezing rain event.  If the center support fails under extreme load, it would not take much to destroy the antenna. To strengthen the support system, rather than using the supplied rope, I am installing aircraft grade cable in its place.

Another source of contention with me, the antenna is not supplied with any type of caps to close off the boom and elements. Left open, wasps and other insects will make my new antenna their home.  To resolve that issue, I obtained a set of vinyl caps from DX Engineering to close up the open elements and boom.  

Additionally, the manual could use clarification and revision.  Some of the written instructions contradict the illustrations, are unclear, or don't seem to match the parts count.  I kept referring to the same set of instructions multiple times to get a clear understanding of the correct assembly.  Another issue is the lay out of the illustrations, logically they should be next to the written instruction for the part of the antenna you are assembling.  However, it is necessary to flip back and forth between multiple pages to find the illustration that is applicable to the written text.

The assembled 40M4LLDD without the final element ends....