The Gap antenna I had was just over 40 feet tall and covered 160- 20 meters. It only used three radials (counterpoises). Are you sure the 160 model is a Voyager? Challenger sticks in my mind. It was
A length of coaxial cable, used to generate a reactance, is about the worse thing possible anyone could ever use. Not only is the conductor length long and generally thin, it does not even have unif
That is an excellent system for a restricted lot, especially if you drop the feedline straight down to earth and put in a good ground system (or the best ground system you can do). You can cover all
With a half-wave dipole...some radiation comes from near the outer ends, because obviously there is some current at the ends. Most of the radiation comes from the middle, however, since most of the
If you can't go through the crawl or basement, just go around the house with a heavy buss strap or wire. Pick up on the other side if you can. Radial geometry mostly affects overall efficiency, NOT
Hi Richard, EZNEC, like any other modeling program, is a tool. The results we get with any tool depend on how well we understand how to use the tool. This especially includes modeling phased systems,
Hi Kevin, If you model a single element in space, you will find it makes an almost ideal reflector at normal spacings when it is self-resonant. You want to be sure to do that at the LOWEST frequency
Even 1dB is a huge increase when copying a signal near noise. The error rate changes considerably here when working CW, when I pick antennas that offer even 1dB more S/N ratio. Most S meters are in
If you set the reflector to the lowest possible frequency you plan on using the antenna on without a driven element nearby, it will be set at the frequency where F/B really starts to roll off fast.
If you have anywhere over one volt on all the pins you most likely have an open ground between the relay box and the RCS-8 control unit. The other option is all the leads are shorted, and that is un
Hi Yuri, The reason you see that "dual polarization" is because Eznec only considers the polarization as two pure distinct polarizations. When you have a tilted wave, it shows up as a mixture of V a
Hi Chris, They are equivalent in the model for arriving at a field vector that is considered with phase and amplitude broken into two distinct parts (useful for calculating the combined pattern). It
In almost any installation the wire gauge is limited by mechanical worries, and not conductor size. 2500 feet of number 20 copper is still good as long as it isn't broken someplace along the way. 73
I've been slack at getting my tests on my web page, but I've already done this. You need to either have an accurate impedance measuring system, or series tune the trap with a negligible loss device
In my opinion, there is NO "better way" to build a dip meter with an antenna analyzer. The sensitivity will never be good. The reason sensitivity is poor is because the coupling inductor has very li
The 259B has a detector right across the output port that measures voltage there, as well as a detector that measures current in series with the output port (which is what the described detector mea
Hi Charlie and All, First let me say I spent weeks on this years ago, at the request of a manufacturer who paid for the time. The goal was to evaluate the article in QST. But what the heck, I could h
Hi All, This idea does not work for wide-band frequency changes as claimed: Using an inverted L for 80 meters, with the L cut for band center at 160 ohms resistance, and fed through 17 meters of RG-7
I don't know how anyone can tell for sure anyway. I DON'T have any specialized lightning gaps or arrestors, I only use grounding that is properly installed and a pair of MOV's on the power line. Wha
Excluding groundwave, which we are not generally interested in, there are two regions where salt water can help. The first and the only major effect is close to the antenna in the direction of propa