We were shocked to find that the existing 1/4 wl performed better than the much taller Vertical. The link below compares the elevation patterns of monopoles ranging from a 1/4-wave to 5/8-wave in hei
BC stations tried 5/8 wavelength antennas to maximize their groundwave coverage. Unfortunately, the high angle lobe produced a skywave that caused severe interference fading at night out in their des
The approximate 3 dB improvement of the radiated field of a 5/8-wave monopole compared to a 1/4-wave monopole refer only to the maximum fields they radiate, NOT to the fields they radiate at __all__
??? ______________ Note that for 1 kW of applied power, the maximum inverse distance field 1 mile from a 5/8-wave vertical is 275 mV/m compared to 195 mV/m from a 1/4-wave vertical. The difference is
Here are a couple of reposts of mine on this subject. http://s24.postimg.org/6nchfpt1h/NEC_FF_vs_NF_Calcs.jpg 1. The NEC far-field pattern for 0.1 km linked abovew shows a maximum field intensity of
The radiation toward an elevation angle of 5 degrees shown in the surface wave plot continues in essentially a straight line, to reach the ionosphere." I'm still puzzled by these statements. Its clea
Most, as in nearly all of the licensed AM broadcast stations in the U.S. use all three of the devices listed below (together) to reduce the probability of lightning damage to their transmit systems w
C. Cunningham wrote: If you get up to 4 symmetrical elevated radials there's not much to be gained by adding more. There's been a lot of work done in the broadcast industry using elevated radials to
From the text of that paper, it appears that the four horizontal radials are attached to the monopole by insulated supports at 4.9-m elevation points above the earth, and terminate there. The coax ce
Guy Olinger wrote (responding to a quote from me that he included): "Such characteristics would apply to the use of elevated radial systems by ham radio operators as well as they do for AM broadcast
The NEC4.2 analysis linked below does not support the statements in the above quote. This analysis compares two 1/4-wave monopole systems over real earth of conductivity 1 mS/m, d.c. 5 -- which proba
Guy Olinger posted: NEC 4.x ground calculation is *tuned* for the *money* paradigm, the commercial MF BC paradigm. It underestimates ground loss where radials would not be accepted as kosher by the F
A response to David Raymond's questions on elevated monopole systems was posted to the listserver on Jan 22, 2014 (link below). http://lists.contesting.com/archives//html/Topband/2014-01/msg00189.htm
The text of my post first including the URL for my NEC study (link below) stated that there was about 0.5 dB difference between them because I hadn't taken the time to trim the monopoles heights slig
You posted that you have NEC4, Mr Olinger. Why not do that yourself then, rather than ask someone else to do it for you? Post your results and the bases for them, as I have done for my NEC4 analysis.
Elevated radial wires perform much differently than buried radial wires. Elevated, horizontal radial wires having self-resonant 1/4 wavelength used as all, or part of an elevated counterpoise for a m
The r-f loss at the operating frequency in a set of buried radials varies with the conductivity and permittivity of the earth in which they are buried. The NEC4.2 study below shows that for poor eart
Here is a clip of a post I made on another website in answer to a question there, which might be of interest here also... Below is a link to a graphic from a NEC4.2 study showing how unequal-length b
K3VAT: Just to clarify: 60 radials are 1/4 wave and 60 radials [appear to be] 1/8 wave, is that correct? Yes, that's correct. _________________ Topband Reflector Archives - http://www.contesting.com/
Just to note that the low-angle radiation produced by monopoles is not accurately shown by a NEC model/study that does not include the surface wave, regardless of whether one or two ground-plane medi