The difference between the two is vastly overshadowed by the difference between excellent, decent, barely, and poor radial fields. Spend all your plotting and scheming time on how to get down 1/4 wav
If you were using flexweave (?), the break would most likely be at an end or a wear point, and the "aerial" nature of your antenna is not long for this world. Good time to bring it down for inspectio
Anyone know a source of such stuff, or a magic Google search phrase that improves on a couple hundred thousand non-pertinent hits about pool cover cloths.... :>) 73, Guy K2AV ________________________
I would guess that most negative press on BOG's originates first with them being a lot quieter overall, both noise and signal. Then in a/b switch tests the regular beverage seems to "outperform" the
By slant feed, I am assuming you mean a wire from the center of your radials (30 ft away from the tower) to somewhere on the tower? I've run a couple dozen NEC4 models on this scheme with various ta
You need to run the numbers for the highest band you expect to be using. You talking about using 20m or 10m? It's hard to make a case for LMR 500 on 160m at amateur power levels. 73, Guy. __________
What we are dealing with is signal to noise at the far end. In no particular order.... After listening to 40m on a big 5 element quad using a K3 in a major contest, by contrast it is quite clear tha
Hi, John. There are three main loss issues that a standard commercial radial field addresses: 1) losses in the radials as a current sink for the shield connection of the feed coax. A standard 1/4 wav
This is a real quandary of ham radio MF use vs AM MF broadcast use where broadcasters are obliged to maintain field strength and patterns as measured (conveniently) at the ground level. Validating p
Many 160m receiving antennas have to assign the ground at the antenna feed to the antenna to supply the current sink for the received signal on the antenna. Certainly a beverage or BOG fits this desc
I would need a copy of your EZNEC model to be sure, but one of the elephant-in-the-room issues in modeling vertical antennas has to do with modeling the ground connection. If you look at the current
Part of the problem is trying to get an absolute value when the local variations in ground basically defeat any such attempts. When I do any vertically polarized antenna modeling, I use real ground a
..snip... In situations like yours the antenna system losses *decrease* as radials are added. Without the losses which are equal opportunity absorbers of all frequencies, the SWR "curve" narrows and
Another approach to interference off band uses a different analyzer, with a BC rejection band pass filter in line. The AIM4170 will allow you to run a "calibration" through the BC filter to a 50 ohm
A 160 meter inverted L can be used quite successfully on 80 and 40. The reason for its non-popularity on the higher bands is that there is no handy-dandy premade MFJ box to tune it, and you can't fee
Given that he was starting with so few radials, I am suspicous that his feedline shield was *not* sharply decoupled and by chance was presenting a low enough impedance as a current sink that the (inf
The use of a phased array for receive for *receiving*, where the main purpose is rejection of an unwanted signal vs. a wanted signal, changes the purpose of the array from the max gain of a TX antenn
Not intending to diminish the excellent accomplishments at Mellish Reef at all, I have certainly modeled a half-wave inverted L on 80m (80 HWL), and was well aware of those results when I replied abo
A BC notch filter that works on 160 has two issues, first that it has to notch out an interfering station, and second, that at each160 frequency to be measured, the residual reactance of the notch mu
There are many options. They are reduced by embraced assumptions or a requirement of only direct 50 ohm coax feed. If one makes the concession that there may be a miscellaneous Z to match on either