Building a Quad-band Folded Skeleton Sleeve Antenna

This post describes the build and test for a quad-band folded skeleton sleeve dipole antenna.

For more detail on the design of the folded skeleton sleeve antenna, refer to my previous post.

I wanted a quad-band dipole for 40, 20, 15, and 10M. I expected the 40M element would also be resonant on its third harmonic, allowing for 15M. I added a third element for 10M, inspired by VA2CY”s diagram showing a tri-band folded dipole of similar construction.

The extra element for 10M is woven into the ladder-line between the other two elements. It is not electrically connected to the feed line (same as for the 20M element).

For an initial test I raised the antenna as an inverted-v. The peak is only about 7-8M above ground.

I am very pleased with the first scan with the RigExpert. A near match on 40 and 20, but with 17M instead of 15M, and a near match on 10M too! The scan shows modifications to the 10M element as I tried to raise it slightly.

Next I will experiment with modifying the 20M element to try to hit the band better.

I expect the fold in the 40M element is what has pulled the third harmonic up to 17M. I’m not sure what, if anything, to do about that?

So, not exactly as intended, but a workable, resonant, quad-band dipole for 40, 20, 17, and 10M. All that in 17 metres total length!