Antenna spike for HF amateur radio

This is an antenna spike I made for another ham, AI5OS. This one uses an SO-239 connector to make the RF connection. The antenna threads into a 3/8-24 nut welded to a piece of 1-1/4 wide 1/8th inch thick steel. The insulator is a piece of HDPE cut from kitchen cutting board.

I changed my assembly method for this slightly. Since this is just a mount, I wanted it to be possible to drive the spike in with your foot. To make that possible what I did was cut a large hole using a stepped bit in the HDPE. This allows me to put the plate with the 3/8-24 nut on the bottom of the assembly.

This spike is made entirely out of steel, which is easy to fabricate with and in my case nearly free since I am fabricating from scrap. It took a little while to figure out the correct materials, but the overall design is simple. The spike portion is a 1/4 inch square section of steel. This is more than adequate enough. If you buy material, you should use round stock.

Front view of the connector

The 3/8-24 nut is recessed down into HDPE sheet

The sheet is bolted on with 6-32 screws, which can be used to connect additional ground radials

Overall length is about 1 foot

The RF connection to the steel plate

The nut means the thread is female, but a screw can be inserted through it to make the antenna spike male threaded