Corrugated Cookie Cutter (Folded Dipole) Halo 10m Antenna

Last crawled date: 1 year, 4 months ago

This is a 10 meter band (30 MHz) antenna that i created and developed based upon reviewing many historical basket weave inductors that were common in the early days of radio.

The issue with a 10m antenna is that as a whip antenna is is pretty long relative to a vehicle size and is usually folded over or uses a 'trap' loading coil to reduce its length. I have developed this antenna that can be for mobile use or small apartment living where size can be an issue. Furthermore this antenna uses a circular polarization unlike a typical dipole which has null gain directions at 90 degrees.

This literal (not figurative) sheet metal 'cookie cutter' antenna is designed for wide surface area using sheet metal to reduce the inner material weight, since RF wave propagate on the surface in a phenomenon called 'skin effect'.

The issue with using sheet metal for an antenna is that it is very flimsy an has little mechanical structural rigidity. I used corrugations to help provide rigidity as well as undulating the horizontal polarization. This sheet-metal folded-dipole antenna has low mass, high surface area and uniform gain.

The materials that hold the layers is sheet acrylic plastic that can be etched, laser cut, or machined. There are acrylic washers that separate the layers as well. The layers are bound with 10mm threaded plastic rod can captivated with plastic nuts to prevent any form of magnetic coupling from steel fasteners.

The outer diameter of the acrylic sheet loop is 345mm (about a foot or 13.6") and the inner diameter of the loop is 225mm, with an arm that extends out 220mm. Acrylic sheet can be any thickness, but i choose an overall thickness of 2.5mm with a 1.25mm etched channel depth.

The mast is PVC and has a glued in retainer ring at the bottom, with a screwed or optionally glued cap at the top.

I am showing LMR-400 coaxial cabling that has (2) clamps: (1) for the core and (1) for the braid.

All sheet metal can be magnetic or non-magnetic (aluminum) but i am showing silver plating for maximum conductivity. The overall length of the sheet metal is 2.4 to 2.5 meters which is about the quarter-wavelength of a 10 meter band antenna. Also which is common with any antenna, this antenna can be scaled larger for lower frequencies (longer wavelengths) or scaled smaller for higher frequencies (shorter wavelengths).

I started this antenna over a year ago, but never finished it as i wanted to get it just right and i am happy with the outcome now.