How To DIY A Shortened 20 thru 40 Meter Vertical For POTA

1/8 Wavelength Radials

As mentioned earlier, it was a bit cumbersome to deal with 40 meter 1/4 wavelength radials in a forest setting. Doing some internet searching, I discovered 1/8 wavelength radials for a vertical antenna are a possibility. Here are a couple of references I found by people much smarter than I on this subject:

Radial System Design and Efficiency in HF Radials – N6LF

Vertical antenna systems, losses, and efficiency – N1FD

So I thought I would give 1/8 wavelength radials a try. Instead of having 33 foot radials, I would have 16.5 foot radials. Additionally, I was only going to use two radials. I know, this is very much less than optimum. But I thought of it more as a challenge to see if this would actually work.

One big problem with a wire antenna when portable, is storage and how to quickly / easily deploy it. Having tried a few different methods and a few internet searches, I stumbled on to W3ATB’s site where he describes using a carpenter’s chalk reel. But not just any chalk reel, but an Irwin Tools Speedlite chalk reel with a 3:1 gear ratio. I won’t go into details here, as he does an excellent job explaining the teardown and modification of this gadget for use as wire storage and quick deployment for antennas.

Here is a photo of my Irwin Speedlite 3:1 chalk reel. It holds 16.5 feet of wire for one of my radials nicely.

For storage of the vertical element of my 40 /30 /20 meter vertical. I used a scrap piece of wood 7 inches long and cut a notch at each end. I then wrap the wire lengthwise. The photo below shows what I came up with. I was concerned that the loading coil would get bumped around and possibly damaged while carrying it in a pack.

Also notice the yellow cord. Since the collapsable fishing pole I used is 20 feet long, and 1/4 wavelength on 20 meters is 16.5 feet, the yellow cord, which is 3 1/2 feet long, is attached to the top of the fishing pole and the red wire is attached to it. This puts my balun on the ground when the fishing pole is fully extended.

So I went to the local Walmart looking for a product that had a round plastic container that this would fit in – and I found it – a round canister of baby wipes! At home I had some packing material from some electronics I had received that is some kind of closed cell foam. I used that to line the inside of the canister. Below is a photo of the vertical element being loaded into its storage canister

Here is another photo of the antenna in the canister ready to put the lid on.