The 4 ground plane wires can be just simple # 6awg solid copper wire. The each ground plane radial is about 5 feet long. I modified these ground radials lengthss according to the ARRL Antenna book. This antenna is in the 1972 Antenna book, but it is not coil loaded.

This antenna loads up on 160m 1.2:1  with NO tuner. This antenna works good with a tuner, on 40 meters, 20 meters and very well on 6 meters. This antenna DOES NOT work on 75/80 meters.