Rick, Your analysis is probably appropriate for a sparse set of elevated radials, each being a significant individual contributor to the radiated field. In such a case, separate radials for each ele
73, Bill WR8K Bill, Two years ago, I ran a Beverage the way you describe. In my case, it was due west, ending about 50 feet short of the line running N/S. It was certainly usable, but there was noti
Tod, Your modeling seems OK, but the above statement is not. Your 57-foot high scenario is too short to have much coupling to the inverted-L. The coupling will be mainly the capacitance between the
This is true only for a straight vertical or a Tee (or top hat) loaded vertical. An inverted-L has significant high angle radiation, making it a good compromise as a single antenna. An "L" that is 5
Responses to questions from Scott WA9WFA: The primary issue with any small receive antenna is avoiding coupling to the transmit antenna and/or other objects that can disrupt the pattern or be large n
Nothing magical about the size -- as a loop, the signal capture is proportional to the enclosed area, and the published dimensions are the maximum that allow it to work on 80M with a simple resistiv
from N3OX: Dan, Dont' know what you'll hear from others, but 50 dB is the minimum I aim for, and 60 dB is better. Depending on your situation, you might find 40 dB acceptable. My primary need for hig
from IZ4EFN: Alessio, Since you say the two antennas have the same noise level, I believe that both of them are experiencing common-mode problems on the long feedline. There are many ways to help, wh
I have updated my web site -- www.aytechnologies.com -- with additional technical articles. "Arrays of K9AY Loops: 'Medium-Sized' Low Band RX Antenna Solutions" (An expanded version of my presentatio
Bruce and all, I have had Beverages near chain link fences in these two scenarios: 1. Feedpoint by the fence and antenna run at a 30-deg. angle. It also crossed over a section of fence at a 60-deg. a
de PA5A: K9AY quote per Dennis W0JX/8: "The loop's published size (25 feet high, +/-15 feet to the corners) is about 2/3 the maximum size for 160M. At one point, I was using one 30 feet high and +/-2
from K9FD from W8JI ______________ Note that these comments are not actually in conflict. What Merv is describing is not actually grounding, rather it is a form of shielding. When I was in the broadc
Neil, Although there will certainly be coupling between the Beverage and radials, the reduced performance may be small, relative to the transmit antenna improvement. If the Beverage wire is appoxima
from Ron, 4S7RO: Ron, It is possible to install a separate 80M 1/4-wave wire at the same feedpoint to make a "parallel" or "fan" vertical. To make it work properly, the two wires should be separated
A minor clarification -- it's not that these antennas are sensitive, but that they are usually installed at limited-size QTHs and end up close to the TX antenna. Yes, the detuning is switched into p
Uli and all, The distance must be sufficient so your measuring instrument does not "see" the elements of the array separately. It also must see a single element as one source, since near-field radia
Frank, Comments interspersed with edited text 73, Gary K9AY -- * There should be little, if any effect due to proximity of the trees. Also, wire length and the exact shape of the loops are not critic
Comments interspersed... That's a good start. Things are not a total mess! Coupling to "something" is the strongest possibility. It can be the radials as well as the radiator of the Inv-L. I would re
First, I'll assume that you have a transformer with separate primary and secondary windings, with separate grounds. This provides common-mode isolation between antenna and feedline. Re-radiation from
_______ Frank, The K9AY Loop (and other terminated small loops) are non-resonant. SWR is largely irrelevant unless you have exceptionally long feedlines or you want to phase two or more identical an