And K7NV would be disappointed if I didn't also caution to be careful that the antenna wind area figures you use are calculated on the same basis as the numbers that Trylon uses to rate its towers. C
K6LL lost one that way. Reported on towertalk at http://lists.contesting.com/_towertalk/2001-January/035713.html 73, Pete N4ZR The World HF Contest Station Database was updated 11 April 03. Are you c
Couldn't the signal produced at the VERY low angles between local sites vary substantially depending on the extent to which a given vertical design is affected by ground quality and/or radial fields.
That was sort of my point. If vertical A works better over a modest radial set than radial B, then a test over such a ground plane would be biased in A's favor. I haven't read your report, and you ma
I modeled a tribander at 70, 80 and 90 feet against the arrival angle statistics for my area (Washington DC) and got the following results (the numbers are weighted average gain in dBi, over flat ter
Good heavens -- no invention claims here. I am a beta tester for HFTA (HF Terrain Analysis) by Dean Straw, N6BV. It will come bundled with the 20th edition of the ARRL Antenna Book, to be released th
A good friend took one down in Massachusetts after 8 or 9 years, and there was so much fatigue damage to the boom (cracking, etc.) that the professional tower guy doing the work advised him just to j
Sure -- it's a little like the old NASA line: "faster, better, cheaper -- choose any two." If you can vary element length, but not spacing, then you will sacrifice either gain or F/B, or maybe both,
Agreed. On the other hand, investing hundreds of dollars in coax and rotator cable protectors won't help in this case either. It's not just single-point grounding, either, but single point low induct
But lightning is much more like RF than DC, according to the Polyphaser book, because of the short rise-time. That's why they put so much emphasis on the use of short, wide, straight (low-inductance)
At least in Version 5.1 of 4NEC2, which I have, the only thing it will do is to generate an INPUT file for VOACAP et al, which are the programs available under the ITSHF rubric. That's quite a lot, b
Shouldn't he also make sure that the guy grips he's using match the lay-up of this cable, whatever it is? Or is EHS by definition 1X7 right (or left, I don't know) twist? 73, Pete N4ZR The World HF C
It would be very interesting to know what measures you had in place when you took the hits, and how the damaging voltages got into the shack. Can you elaborate a bit, Billy? My problem is that I can'
Here's a table of gain, take-off angle and F/B versus stacking distance for 6-element OWA 20M yagis, as computed by NEC-2. In all cases, I used the 1X/2X rule -- a classic choice for cancellation of
I've been doing some modeling of various stack configurations, to explore the effect of various feedline options, and I thought the results might be of interest. The basic stack is a pair of Force 12
I don't know how to do this, but agree that it would be a closer simulation of the real world. I've seen models of dipoles with transmission lines attached, where the physical shield is represented b
In some instances being in the other elements' fields may not matter much, particularly if the feedline is taped to the boom and mast, and then goes to the bottom of the tower inside it. What I was w
My house -- a farmhouse -- came with an array of 6 lightning rods, complete with woven aluminum down-conductors. Lightning rods are fairly common on houses out here. I am very unclear on whether they
I wonder if anyone is doing anything similar for the Force 12 EF-240S/C-4XL/C-4 series antennas -- anything that uses the EF-140S dipole. It strikes me that substitution of coils (plus cap hats?) for
Can someone who has W2PV's book tell me what he says is the nominal free-space gain of a 2-element 40m DE/reflector yagi on an 18 foot (roughly .27 wavelength) boom? I'm doing some modeling of a shor