Pete and all, Here is what I have developed for K9AY Loop modeling... Remember, although the antenna was "discovered" by modeling, all the hard data on appropriate terminating resistance and pattern
Thanks for the nice compliment, Guy I'll try to flesh out these notes with some plots and put them in the TECH NOTES section of www.aytechnologies.com in a week or two. Gary, K9AY _____________ ...et
I also have had problems over the long term with "sealed" connectors. Back when I was in broadcasting, I was always getting water in supposedly weatherproof N connectors, even when sealed with rubber
Art and all... It is not possible to accurately model the K9AY loop -- it is connected to ground, and such connections result in significant uncertainty (and possible major errors). NEC can't reliab
After recent discussions on the Topband and Antennaware lists, I took = some time to review modeling of the K9AY Loop. At the suggestion of = WX0B, I took another look at an accepted ground model for
Dan, I have seen this before, but it's been a long time and can't recall the particulars. Either your SWR meter is lying to you (calibration or someting broke) or there is problem that is taking a di
Dan, I'm willing to bet that you have RF floating around on shields and grounds. The added coax changed the system enough to reduce the problem in the shack, but increase the RF in the Satellite syst
Dallas, It's difficult to get accurate measurements of trap performance, but a few general points are: * High-Q traps with inductors and fixed capacitors are the lowest loss, but voltage breakdown in
Dave, As a 'rule of thumb' the captured signal power in small loops is proportional to the area enclosed by the loop. Twice the area = twice the power (3 dB). The typical dimensions given for these l
____ ____ I agree with N6RY ... and be VERY careful about some of the early ham radio references you may find. These loops were not well understood by the ham community -- which is surprising since
Jim, Some years ago, I worked with another ham to feed his two HF2Vs in-phase (broadside) -- the biggest problem was getting the two antennas to have identical feedpoint impedance. It took plenty of
Jan, You did the #1 best thing by using a large diameter. Any improvements with a neater winding will be small. Same goes for larger wire or tubing -- the theoretical improvement may be hard to see.
Dave, One rule of thumb for the distance considered to be in the "far field" is roughly 10 times the height of the vertical, or the spacing of verticals in an array. At this distance, there is essent
Ultimately, the far field is where it is impossible to distinguish the radiation due to distribution of current along the antenna from that of a point source. This can be quite different for various
Guy, Actually, the regulatory bodies are very interested in skywave propagation -- it is the basis for nighttime interference protection among AM broadcast stations. But you are correct that skywave
Fred, The shielded loop is implemented only as a small-size receiving antenna (less than 1/10 wavelength diameter). The shielding has the sole function of improving balance to ground and surrounding
I have also recently heard stories of big interaction problems with the new XM240, worse than the older 40-2CD. The only other commercial antenna I know about is the old KLM 2- and 3-element 40M beam
Andy, As others have noted, EZNEC assumes that you have a matched feedpoint, so any loss in the transformer or other matching network should be added to your calculations, although it's probably qui
Andy, Some time ago, I also did extensive modeling of resistive-loaded verticals, hoping to find a configuration that had good broadband characteristics and moderate loss, or at least a method of con
Oops, I need to retract the statement: The above configuration has a null straight up, like a vertical. This is the closest I came to broadband "element" with a well-controlled feedpoint impedance. T