Tom, with this ground system and 90 degee monopoles I measure 5 ohms ground loss on 7 to 28 MHz. With the 30' vertical I measure about 10 ohms on 1.8 and 3.5 MHz.
The 7 MHz measurement agrees with the N6LF papers (90 deg monopole and 1/8 wavelength radials). I have no evidence that would lead me to doubt the measurements of the other bands. 160 meters measurenent: 15 ohm base R 2 ohm radiation resistance 5 ohm cool loss 8 ohm ground loss (rounded to 10) This is the accepted procedure for measuring base referred ground loss, is it not? Dave WX7G On Sep 27, 2012 7:54 PM, "Tom W8JI" <w...@w8ji.com> wrote: > I am presently using a 30' base loaded vertical. The ground system consists >> of 90 radials from 12 to 25 feet. The base referred ground loss is 10 >> ohms. >> > > The problem is we really can't measure ground loss at the base. > > Let me give an example.... > > A 40 meter vertical here, 1/4 wave tall of fixed length. > > Four elevated radials had less than 40 ohms feed resistance. About a dozen > buried radials had around 60 ohms base resistance. > > Field strength was identical despite the resistance difference with the > same length resonant radiator. > > Others have measured the same type of thing, and it is easy to duplicate > results like this. > > 73 Tom > > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK