80M - 10M Vertical
	I went around the neighborhood and collected a few old CB antennas ("If you don't want that any more I can take it down for you"). With these parts I made a twenty-one foot vertical with six 110 Inch radials and mounted an Icom AH-4 antenna tuner at the bottom. This is on a telescoping steel mast up at about 44 feet with the mast grounded at the base to an eight foot ground rod. This loads up from 80M to 6M just fine, too little low angle radiation on 6M. When I modeled this with NEC the pattern looked good on 80 through 10 until I put the mast and guy wires in the model. Now some bands look good (10 through 15 and 80) the others are ok but have too much high angle radiation. That is according to the model, in use it works very well. Shortly after I put it up I talked to a fellow in Alaska (I am in Washington state) with only five watts on 17M and also made a contact with someone at Rothera Station Antarctica with 100 Watts also on 17M. I chose 21 feet as this is 5/8 wave on 10M. It seems to do ok on 6M also.
Update Dec 14, 2012 Here is an update because someone emailed me a few questions about this project and this was my response to him. The actual antenna that I started with was a 1960s era CB antenna called the "Super Magnum". I do not remember why I chose 110 inches for the radials, it does not seem to be resonant on any amateur bands. The length of the vertical radiator was chosen to be 5/8 wavelength on the highest band the antenna was gong to be used for as this would give the lowest takeoff angle. At higher frequencies the antenna still works but the radiation pattern starts to break in to lobes with a large amount of the signal going mostly straight up. The current version of this antenna that I am using is a three band trapped vertical (10M, 15M and 20M). The problem with this antenna is that on 20 Meters the radials need to be more than 5 meters long. It seems to me that you need at least 3 radials for each band for the radiation pattern to be circular but if you don't mind it being a least a little directional then two would do. Any future vertical antennas I make will be limited to 2 bands so that I can have at least 3 resonant radials per band. I will also try a 10M, 12M and 15M version with radials resonant on 10M and 15M. If the radials aren't resonant then they don't shield the vertical radiator from ground or from the coax below the antenna. I highly recommend a book on vertical antennas called "Vertical Antennas", it was written by William Orr and Stuart Cowan (ISBN 0823087107). It is not an in depth exploration of verticals but gives a good amount of information to get started and has several real good examples to experiment with. I have seen this for as low as 15 USD and as high as 35 USD.