"Earth ground affects transmitted RF because the radiated RF impinges on the earth and is absorbed and reflected, the ratio between the two being affected by the parameters of the earth (conductivity
"If you connect a wire from any point on the dipole to ground, current will flow." That corrects the typo. I wanted to add that one way to visualize things is to employ the image-current model that a
https://i.postimg.cc/8k2w1vDW/ant.png This models a 20-meter dipole 20' above ground with a common-mode current path. The vertical wire, which is connected to one side of the feedpoint, represents th
"N6LF has published a lot of great work, really scientific studies of ground systems for antennas. His website is a great resource." Jim, Rudy's website is going away because Typepad is folding. He d
"Reference my early example of a portable rig with no connection to ground anywhere." Dave, I'm curious what you made of my antenna model that showed common-mode current flowing to ground from the co
"I already answered that." Dave, the antenna model I posted contradicts this assertion you made: "I already did with the example of a floating portable setup. Current requires an E-field to push it.
"RF isn't DC ... it doesn't just flow to the earth and disappear. It flows back and forth every half cycle." That brought to mind the AC/DC power rivalry of the late 1800s. George Westinghouse, with
"It just shows current going back and forth between the earth and the coax." Dave, I don't know what you mean by back and forth. In my model, the ground wire simply has current. It is about three tim
I've updated my coil inductance and Q calculator and my ground probe calculator with improved plots: https://k6sti.neocities.org/coil https://k6sti.neocities.org/gnd If you don't measure your soil wi
"The great thing about a vertical is that it really 'wants to work.'" Whenever I encounter this notion, it provokes mental bedlam that includes a chaotic mix of surprise, appreciation, exasperation,
"Anyway, in some cases they ran stupid long radials but in very limited directions (like a gob of them over just 5 degrees then 10 degrees etc etc) then they measured the verticals azimuth directivit
W6FB: "In this design the ground wire is actually a 1/4 wave ring that wraps around the base of the antenna." One issue with a compact counterpoise is that feedline decoupling becomes more difficult.
George, if you're willing to modify the DE mounting, this writeup shows how to overcome the gain degradation all OWA designs exhibit: https://k6sti.neocities.org/owa The designs shown are examples. I
I ran across a 1979 report that describes measurement of a system to enhance low-angle radiation for HF verticals by adding several "ground wires" (radials) in the direction of propagation. I think t
Rudy's website is alive again at http://www.antennasbyn6lf.com/ Brian _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@
I'm forwarding the issues to Rudy. Security false alarms are common. What I do to check a suspicious website or download is to pass the URL to VirusTotal: https://www.virustotal.com/gui/home/url It w
From K6RMW, who set up Rudy's website: Contact N6LF directly if you experience any further problems. Brian _______________________________________________ ____________________________________________
"I can't think of any reason why an antenna would be "quieter" other than it having a tighter pattern, either horizontally or vertically, and therefore discriminates against background noise better.
If you can manage it physically, one trick to lower receive noise is to vertically stack two shorter Yagis rather than using one long one. The spacing will direct a null toward ground. At half-wave s
One correction: the null below reappears at 1.5 wavelength spacing, not 1 wavelength. That's probably wider than optimal for maximum forward gain unless the Yagis are really long. The nice thing abou