CQ magazine ran a construction article about such an antenna in either 1992
or 1993.

I started one for 30 meters, but never got around to finishing it. I think
the 2 5 foot sections with the wire coiled on them are still around here
somewhere.

My suggestion is that unless you are wanting to make it more portable, use a
full 10 foot stalk of PVC, rather than 8 feet. That will mean less loading.
If you need to make it for quick storage as I was doing for an apartment
balcony installation, use 2 5 foot pieces with a coupler glued to one of
them, and a short clip lead or terminal wire to connect the two sections of
wire.


The center conductor of the coax feed line connects to the antenna at the
bottom of the coil. Since you are using a half wave of wire, radials won't
be as critical, but will help. They connect to the shield of the coax.

Another simple option for 20 meters and above is to go with a full size
quarter wave wire inside a PVC tube. This would be more or less 16 feet for
20 meters. Ground radials would be essential for this antenna to perform at
its maximum efficiency.

While ground-mounted verticals do work well, you will generally find that a
vertical with the base several feet above ground will blow them away.

Either way, build whatever fits your physical situation, and have fun using
it!

K5XU