Quite possibly you are experiencing dielectric heating of some component of the antenna itself, and are losing connection when some part gets hot enough. Most of those kinds of antennas do not really
Posted an earlier version on topband (I think, still getting used to Gmail interface) Part of the problem is trying to get an absolute value to mean something when the local variations in ground defe
The length on 40 makes it excitable on 20 meters, simply due to the proximity, with or without the feedline attached. Putting EDZ's for 20 and 40 in proximity probably won't work in the ordinary sens
Admittedly from a bit of a pessimist about manufacturers using the least in products they could get away with instead of the best... Any one of the components you mentioned could give the behavior yo
Water wicked into the shield weave present in coax by being broadly lossy, which LOWERS swr rather than elevating it. It's a fairly weird problem if it only shows on one band. Water logged coax CAN c
The C3 series from Force 12 can be tuned on 17 and 12 with patterns. One of them is reversed if I recall correctly, but useable. But those antennas don't use traps. I would be wary of tuning trap tri
Perhaps one of the reasons is that the best gain and pattern is not necessarily at a 50 ohm zero reactance point on the DE, in some cases "miles" away from 50 J0. I found this consistently with a lot
Know several free programs, but not the source code. Anyone else? The NEC4 professional license comes with Unix-based source code, but that's confined to the community of user's and changes must be s
Unfortunately you describe a file which is five years old. The method and combination files may likewise be as old. If you cannot get in touch with authors and/or a user's group for the software, thi
The real problem in the picture that you paint is that the break point for center loading is just that, a structural weakness for something as tall as 60-70 feet. The center loading is in the way for
Depends on whether your main goal is to work people easier, or it's an intellectual pastime. Frankly modeling and EZNEC are a great pastime what you do about the dirt. 73, Guy. ______________________
Four and Five. The impedance may change by raising the ends, but your problem on 15 makes me suspicious of lengths. Multiband antennas are very touchy. Some recommend a second G5RV, scaled with 40 me
If you have a single feed point, I or V is immaterial. SI or SV is used put a feedpoint at a wire junction, as in a Vee antenna. Mark the two connected points as SI or SV. When you have more than two
I have the PRO/NEC4 license (which cost me some change) and need the heavyweight often enough (mostly for buried wires). Though it might be my advancing age (and a few other things my wife might tell
You must then remember that to get the results, you have to something specific to FORCE the desired current ratio and relative phase used in the model. V sources may not deliver the results for a giv
When I first started using modeling software, the temptation was to accept those results as real and I quickly succumbed. I came up with some models that showed excellent gain and put one up. I quick
I have all the scars and memories of wasted time that would prove otherwise. Take models as gospel, and it will get you sooner or later. Don't go investing any of my money in unverified models. With
Dennis, I'm also going to post this this reply on Antennaware reflector, with only the question quoted as it would seem to be of general interest and (unfortunately?) has a complex answer. ...snip...
Always model it. You might be the one that discovers THE CLUE to solving the ground radial problem. SOMEBODY has to stumble over it in the dark SOMETIME. Great minds hasn't worked. Need some plain ol
One other thing is that UHF and coax with a waterlogged shield do not get along well. When I was maintaining a repeater, we spent a lot of time renewing water seals. A bad seal and water in connector