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As I recall, peak gain was somewhere between 1/2 and 5/8 wavelengths apart, but I could be wrong. I do know there is an upper limit of distance between said current nodes, and I am thinking that 9/10 (i.e. 0.9) seems a bit high. I could be wrong as it has been a while since I've modeled this...

Its strange that I don't recall seeing that Cebik article before, I'm pretty sure I read them all at one point or another... I was never fond of the 5/8 over 1/4 or 1/2 collinear idea. I think part of it was I was worried about how the extra 1/8 wavelength of out of phase currents would mess...

It would work fine. If you use coax and can't make a matching circuit yourself, use a remote autotuner. Or the way I prefer it is ladder line to a manual tuner on the desk. Either way, a full wave dipole will have a pattern much like a dipole, except stronger peaks broadside of said antenna...

Are you looking at vertical or horizontal? The DB

Metal pulley plus metal wire without insulation around them that I can see. To RF they will act like a single big piece of metal in a disc shape, not individual wires in a coil. This is a classic shape for a cap hat. The thing is, it is in the worst possible place to put said cap hat, namely...

A few thoughts on this antenna. There is a lot being shown in this image that relates to how this antenna works. A few things that strike me with this image. The first is the feed-point that feeds the antenna seems to be under the label that have covering up the motor. There is some method...

There is an older term that I haven't come across in radio lately when referring to the relationship between TX and RX when it comes to tuning an antenna. That term is reciprocity. It states that anything that affects TX or RX will effect the other equally and in the same way. This is limited...

I won't argue against that, modeling shows the same. The real question that needs to be asked, however, is how much more efficient is the cap hat over a loading coil... What does you book say? The DB

There is a stepped diameter correction built into 4nec2. I don't know if its the same as the one in EZnec. I played with it once or twice, but even going from the entire element being the smallest diameter in the element to the largest diameter in said element hasn't made much of a difference...

Cap hats actually do have this effect, to some very small degree. Unfortunately you will never notice it as just having a cap hat will add more loss than whatever you would gain from said current manipulation. The only place with any antenna where I've seen capacitance appear to have a...

I may not mention this much, but I like it when people get these old original antennas and restore them. And this being one of my favorite antennas to explore... Keep up the good work. The DB

I would suggest reading the EZnec user manual, (that is a link) they have a very good description in there, and if you search for average gain, it comes up a lot all though out said manual. If you want accurate gain results, it really is important to pay attention to. Essentially what Average...

I'm more of a 4nec2 user, although I have used eznec, and the method is basically the same. The recommended way to add the hairpin match is to break the driven element up into three separate wires. From one tip to where one side of the hairpin attaches, the area between the two points the...

So, this is an antenna that is between 5.5 and 6 feet long and it uses a planar loading coil. All a planar coil is is a flat coil, nothing more. They also loaded part of it up with, essentially, techno mumbo jumbo as read from the antennas manufacturer's literature. MEG... It stands for Mean...

That is true. Just raise hell until they put them all underground in the areas you drive... ;) A friend of mine used to run an autotuner right before a 102 inch whip on his pickup truck (mounted front left corner of the bed). He loved it, then when he got a new vehicle, at the suggestion of...

Assuming the same mounting place, and a remote autotuner, you would get better performance if you used the 15 meter 1/4 wavelength length. In fact you can comfortable go longer than that by quite a bit. The DB

Common question. It shows up here every so often. If you don't have any problems with the antenna setup, then adding the radial kit will make so little a difference you will never notice it. There are, however, problems that said radial kit will fix, in which case you very well may notice a...

I remember those days. Said amps would be run on the ragged edge to the point where everything had to be perfect, and even with said perfection, many dind't last long even when run at 12 volts and under ideal circumstances. The problem is many people bought said amps thinking they were "the...

That is an option, and if you or the op chose that path I would have no complaints. In fact, it was listed at the top of my recommended list. Although calling it "maximizing efficiency" is at best a stretch, especially from someone who is willing to "deal with" said additional loss. The OP...

The problem is the fact that the antenna isn't going to be a tuned antenna. Lets take a look at what happens to said efficiency when SWR goes up, this is with 220 feet of LMR-400 at 27.2 MHz. Here we have SWR in the first column, dB loss in the second column, and percent of transmitted power...