I bought about 100 of them for about $5 from some guy in Canada a couple of years ago, but I can't find him any more. Here are some other possibilities ... http://www.universal-radio.com/catalog/part
Check out the last two pictures on this page. The coax makes it look more like a support pole for a dipole or something, and the pole itself looks like those 4 ft surplus military interlocking mast s
I have to run an errand and can't check it now myself, but doesn't EZNEC allow you to define two different ground zones (radial distances from center)? If so, you should be able to compare the result
That's not really true. Elevated radials don't have to be resonant for an antenna to work well, or even be resonant. It is possible, for example, to have the COMBINATION of the vertical element and t
No, I didn't say the same thing. I didn't say that it was required for the system to be resonant, and it isn't. It is just trickier (sharper tuning) to tune any sort of off-center feed to resonance i
I've always heard/read that the signal radiated from an antenna positioned several wavelengths down the hillside from the peak of a mountain (and pointed away from it, of course) is stronger than the
This showed up via a Google search using the key words in your post. http://www.kkn.net/~k5tr/blanco/6ele_10m_OWA.html 73, Dave AB7E _______________________________________________ __________________
Ignoring the traps, the current distribution in the element is a sine wave with a maximum at the center and zero at the ends. The current does all the radiating, so I don't see how four inches at the
3 inch ABS fits very nicely over 3 inch irrigation tubing, and Home Depot sells black "plastic" toilet flanges that will fit over the 3 inch ABS. The toilet flanges are super tough and already have f
Admittedly I haven't used that much 3 inch irrigation tubing. I have a couple of lengths of 3 inch diameter (72 mil thick) stuff I bought from Rain-for-Rent a few years ago and it was almost a perfec
The antenna described by K9YC is in fact fed at the center as can be verified by its feedpoint impedance, which is essentially the same as any other dipole. 73, Dave AB7E ____________________________
I can't think of any advantage to a helically wound antenna. Structurally they are more complex, and electrically they have several disadvantages, most of which have already been pointed out here. I'
How so? Even a 0.5 inch cross section the length of a shortened 40m or 80m antenna adds up to more area than the cross sectional area of a coil, with a greater percentage of it up high where the leve
All true. And thinner conductors have slightly higher inductance than fatter ones of the same length. 73, Dave AB7E _______________________________________________ ___________________________________
1. Solder does not break down due to UV. 2. The lead in lead-tin solder will react with moisture to form a white crumbly oxide. Exposed to the elements, the entire joint will eventually become porous
Answer 1: Likely so, although with a half sloper the tower and everything connected to it becomes part of a complex radiating system so it's pretty much a crap shoot what the interactions are. Answer
That statement reminds me of the posting here a year or so ago from the guy who felt that since he had never fallen while climbing his 60 foot tower he didn't think there was any need for him to wear
Let me clarify for you ... there is a huge difference between not over engineering something and not engineering anything at all. Basing a decision solely upon experience falls into the category of n
Doug, What you originally stated, and what I originally responded to, was "real life experience which trumps any theory any day." I totally disagree with that statement, with countless historical exa
What you say makes sense. A structural engineer friend of mine spent several years designing concrete bridges and similar structures. He told me that, in theory, smaller reinforcing elements (assumin