As somebody who has been a licensed amateur radio operator since some time in the mid-1990’s, the 6m band has always been interesting to me. Since I never had the equipment to venture out on it, it has mostly been one of those mystery bands that I heard people talk about, but never was able to participate in.
Some time ago, I pickup up an Icom IC-7100. While it has built-in support for 6m, I didn’t have the antenna equipment to do anything meaningful. The dipole strong in my attic never cleanly tuned, so I ignored the band.
A few weeks ago, the Youtube Algorithms thought that I might be interested in K2CJB’s video on building a 6 Meter Square Halo Antenna. The fact that the build was based on a plan by PA3HCM didn’t hurt either.
So, after obtaining some copper pipe to augment what I already had in my junk pile, I figured out how to solder copper and started the build. All in all, the project is very straightforward.
I did make a few alterations:
I added a spacer between two pipes to which the feedpoints connect. I 3D-designed it and printed it using PLA filament. It is available here as squalo spacer v1.stl.
I designed and printed the insulator. Note that to tune the antenna to be resonant at 50.3 MHz, I had to extend to spacing to 4 3/8 of an inch. The insulator is available here as squalo coupler v2.stl.
I attached the antenna to 1.25” PVC pipe. To make sure that it didn’t go anywhere, I created two mounting brackets. The design for them is available as squalo mounting bracket v3.stl.
The end results works. With the antenna only up some 4.5m above the ground, I can work the US East Coast north to south. The antenna’s lowest SWR is 1:1.08 at 50.3 MHz with a 51 ohm impedance.
Next step is to shorten the feedline and get it up higher.
This was a fun project!