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There are several options. 1) You can measure the impedance of said antenna and build an antenna tuner for it. This would allow the use of said LMR-400. You would get 1.397dB of loss in the coax (or with 100 watts in you will get 74.495 watts out) and a little more in the matching circuit...

I would start with four 1/4 wavelength radials at the height of the vehicle's roof. Easy to make and typically very effective. Looking at the model, when it comes to a segment at the end of the wire and placing a source there, make sure the end of the wire is connected to other wires. If it...

I model primarily in 4nec2, but both EZnec and 4nec2 use the same nec2 engine. When modeling a coil, the software will make adjustments on inductance and capacitance within that coil, but most people use small straight lines, and because of that, what the software calculates will be off to some...

If changing the routing or location of the coax changes SWR then you have one of two issues. Essentially the easy description for both of these is you have antenna currents flowing at places you don't want them. The most common cause is common mode currents. A lot of people will falsely...

There is no noticeable difference between SWR and Resonance. There is also no noticeable difference between 2:1 SWR and 1:1 SWR. The difference in both of the above is so small you will never notice the difference. In most cases, getting that antenna 5 feet higher will make more of a...

There are three different ways to design a Yagi antenna with three or four elements. One is gain, a yagi antenna with peak gain in the forward direction tends to have a pretty significant secondary lobe facing the opposite direction. I actually know a ham that thought his antenna was pointed...

So you mentioned above 37 ohms and now you post a picture and reference to something that says 35 ohms. I guess they are somewhat close relatively speaking... I would have so many questions about the antennas you made and how you measured them that it isn't even funny. Based on my experience I...

I'm curious as to where you got this idea, its at least the second time I've seen you post this. The problem is, it isn't true. If a 1/4 wavelength vertical antenna is over a perfect ground, then it will have 36 or 37 ohms of impedance. But four radials does not a perfect ground make. The...

The speed of light is 11,802,852,672 inches per second The frequency for CB channel 20 is 27,200,000 Hz To get the wavelength take the speed of light and divide that by the wavelength... 11,802,852,672 ÷ 27,200,000 = 433.9284... Then divide that by 4 for 1/4 wavelength... 433.9284... ÷ 4 =...

I've said several times in this thread and elsewhere that you won't notice the difference between however you choose to tune your antenna, included in that quoted post. Part of the point of the thread was to challenge a concept that is widespread but no one has ever demonstrated before. The...

If you look under DX Gallery link above and click on my name, in there is an album called "Does resonance show max gain?" This has the images that were used in the initial post of this thread. Back when I posted it, I was able to link the images in an album on this forum directly into a post...

Looking at these models closely, I'm curious where you got these models? The first and third models, that is the Sirio SY 27-4 which is said to be from the Sirio web site, and the Maco M103C which is said to be from the Maco web site. The curious thing about these two models is they screem...

According to This coax loss calculator, a 150 foot run of RG8x with a 1:1 match on the antenna end, 100 watts in will get you 58.498 watts absorbed by the antenna. There is 2.32 dB of loss, all of it from the initial pass through the coax. According to the same calculator, a 150 foot run of 450...

The short and quick answer is, some people notice a difference after installing said ground plane kit while others don't. Now for a slightly longer explanation... The ground plane kit, in and of itself, won't improve performance enough to be noticed. For that to happen you must have a problem...

Is it something like 2 meter and 70 cm ham bands where the frequencies in question are harmonically related (or at least close)? Is there some form of matching on the antenna? Is there some form of inductive/capacitive loading on the antenna? How did they achieve said multi-banding? Although...

This is the specific text he has highlighted. When you add a capacity hat to a 1/4 wavelength antenna element, efficiency goes down. This is a form of loading and all forms of loading have this effect. But this is also that "less efficient" statement that so many people get hung up on, when...

Inductance and capacitance have the effect of changing phase. It is literally their only job when it comes to antennas. This effect, however, has a wide range of uses, from shortening 1/4 wavelength antennas (possibly the most common use) to antenna matching. Changing the phase in this...

I'm surprised I didn't post anything about this back then, I must have been busy when this conversation was happening... I agree, the a99 is not a 1/2 wave over 1/4 wave. That came from advertising for said antenna, which is apparently enough to get some people to believe it regardless of any...

It wasn't the DDRR that I was analyzing the vertical polarization models show, it was the Super Sinner, and later a dipole antenna mounted horizontally in the modeling software. The DDRR will definitely have a vertical component. The DB

First things first, I wouldn't get hung up on the magnetism of the loading coil. It is a thing, but not something we are typically concerned about. A step in the right direction would be their inductance, but that is really only half way there. What we are really concerned about is the...