This is a center-loaded, 1/4-wave vertical that I made for 40-meter
pedestrian mobile operating. The antenna starts with 9.5 feet of
20-ga stranded wire at the top. This connects to a coil made with 15
turns of 18-ga wire wrapped around 2-inch (thin-wall) PVC tubing and,
finally, a 10-foot length of 20-ga wire ending with a banana plug. The
antenna plugs into a small mint box which allows me to add a
counterpoise wire and coax with a BNC connector.
Gary, N5ANF and I tested the antenna on March 12, 2005 from an
8,000-foot mountain top here in Colorado. The antenna was supported by
a 20-foot fiberglass fishing pole. That in turn was placed on a 5-foot
piece of PVC pipe and lashed to the tailgate of my pickup. With five
watts from my FT-817, we worked stations on 40-meters from Oklahoma and
Kansas to as far away as New York and Georgia, with a 56 report of my
QRP signal from the GA station.