40m 3 Element Vertical Yagi Antenna

We’re putting together a Multi-Two entry for CQWW this year and it’s pretty clear from our experience with CQWPX that we not only need gain to the US on 40m but we need excellent front-to-back ratio. A new antenna was required.
A two element yagi was considered but we don’t have a tower for such a beast. We did though have various 10m fishing rod blanks and a load of aluminium scaffolding tubes. With some analysis, we feel we can build a high gain array utilising Yagi’s principles of a driven element in the middle and a reflector and a director element front and back.

Original modelling was conducted with MMANA however, the team has recently started to convert to modellilng with NEC2. James’s NEC model confirmed my 5db gain using MMANA at 10 degree take-off angle.

40m Three Element Vertical      3d Far Field Vertical Yagi     40m Far Field

The feedpoint for each element will be at 9 meters above ground using 6 meter scaffold pole sleeved with a 4 meter inch and a half steel pole. The 10m Sky Blue Leisure flag poles sleeve to the inch and a half steel poles. I’ll take some pictures tomorrow of the build.
Make no mistake, these will be monsters with 8 raised radials per element. Today, I made the insulated guying blocks for the radials. This is going to wipe the floor!

Watch this space.