One can get structural fiberglass shapes fairly inexpensively. Cost wise, it's about the same as aluminum in the same size, and the strength is, to a first order, the same as aluminum. It's twice as
Fascinating question... First question for you: What kind of power lines? LV feeders (240V), MV distribution stuff (14-30 kV) or HV transmission lines (100 kV+). They'll all have different kinds of i
You need to separate "grounding for lightning protection", "RF grounding", and "safety ground" as concepts. If you're driving the tower as a radiator, then the ground at the tower is the "RF ground".
But NEC is reallly addressing the safety ground, not coax ground, which can (and might) be different. I've just been going through the IEEE Emerald Book (IEEE std 1100) parsing it out, and it has muc
I misstated the approximate location of the Magnetic North pole as 70N,100W. As everyone knows, it does move, and one can probably identify the age of the reference by the latitude they cite. In 2002
The Canadian site is actually fascinating... Lots of stuff there about how the magnetic field is NOT adequately represented by a dipole (What, no bar magnet in the middle of the earth?)... This is on
Indeed, while the various TDMA cell phone systems use GPS clocks for sync (such as the Z3801s you see available surplus), I don't know that the average phone actually gets a time message. Certainly,
What element currents did you assume for driving point Z? Phased 90 degrees each step? Apparent driving point Z changes with element currents, of course. I've been looking at phased arrays a lot, and
Just to check ballpark Mutual Z numbers.. for dipoles in free space for halfwave dipoles in free space .25 lambda R21= 40.9 .5 lambda , -12.7 .75 lambda, -24.8 (@ 0.7 lambda) to -18.6 (@0.8 lambda) R
Or, your local PE, after reviewing the old calcs, might find that the design meets the new standards, as well as the older ones. Or, for instance, you might find that the maximum antenna area might n
hmmm.. it used to be (pre 1970s) that you could approximate the change in deviation by 1/2 degree per decade (in California). But now that the magnetic north pole seems to be moving quite rapidly (40
While not denying the putative benefits of healthy exercise in the outdoors (at least, that's what I tell the kids), a trip to the local equipment rental place might turn up some things that will mak
If you had to get a building permit for the tower base, it's unlikely that the "mix in the hole" approach will meet the inspector's approval. Not enough process control to ensure that the structural
SNR usually applies to a link (i.e. transmitter to receiver) Are you assuming that the noise distribution is uniform around the antenna? Then the SNR would be the incoming signal power density, times
This brings up an interesting question... has anyone ever done some reasonable quantitative performance measurements on "non-RF" relays. Sure, they aren't nice vacuum relays, and they probably have a
Or, a 4 horse or stock trailer.. certainly it will take the weight.. might be a challenge getting it in the door of the trailer. Almost any tractor or front end loader can pick it up. MA-550 I'm it.