It's summertime, and I'm thinking of improvements to my antennas. In particular, I'd like to have a low-noise receiving antenna for 40, 80 and maybe 160m. This would likely be used for domestic stati
Friend of mine is building a new house, and he doesn't want to pay his Satellite TV service $6 a month for local channels. So, he's going to put up a ~50 foot tower with a TV antenna, and he came and
For a bracketed installation, you may have to seriously limit the amount of antenna you can place at the top. Depends. 1) What is the maximum wind velocity for your county? 2) How much antenna area d
For someone who claims to have a mechanical engineering degree, this is completely absurd! Consider -- the wind pressure varies with the SQUARE of the wind velocity. Antenna support structures design
Now that it is summer, I need to make some improvements to my station on the low bands - particularly 160m and 80m. Right now, I've got a 15m tower with an A3S on top. I have a shunt feed made of two
I plan to add 12 more this summer. I went from 4 to 13 last year. Didn't make a big difference on 80m, but it sure perked up the 40m 1/4 wave sloper. Retuning isn't a problem. The real question is, w
Important questions. What height will the brackets be? If you study the Rohn catalog, they pretty much recommend using more than one bracket, although if the top bracket is below 15 feet and the towe
While this is interesting -- why both to get something special for this? Any tower-owning ham ought to have a bottle of No-Al-Ox or Penetrox anyway, right. The particles in the anti-oxidant are zinc,
I don't think this is generally true. It all depends on what the limiting structural element of the tower is. Only the Engineer knows that for sure. And those "slack" guys aren't just infintesimally
Also keep in mind that the Earth's magnetic field is affected by the surface composition. On my Atlanta area Terminal Charts, there's a note around Stone Mountain which indicates that compass deviati
The models show better F/B than a 2 element yagi, but similar gain. Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901
Instead, I suggest he rent a small mixer from your local home improvement store. Mine cost $40/day, and I mixed 28 bags of sacrete in a little over 2 hours. (two 60 lb bags at a time). I can't imagin
Buy two sets of 4-wire trailer hitch connectors. Reverse one of the sets so you don't get the two sets confused. There, for < $20, you have an 8-ple water resistant connector set for your rotator....
I did the same thing -- but I used two four-pin sets and just reversed one of the sets. That way, you can't plug it in backwards. Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net Quote: "Not within
Why bother with Nicopress sleeves when you can use pre-formed guy grips? (Unless you're building an airplane, of course, then Nicopress are the only acceptable alternative) Bill Coleman, AA4LR, PP-AS
Paul, I hate to disagree, but chemistry says just the opposite. Polyproplene rope degrades quite quickly in the sun. Within a year, it will be so brittle and will shed fibers everywhere. It is used i
So, uh, who would climb such a tower to install the tribanders? Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901
Since I sent this to you personally Tom, and you have answered on the list, I'll answer on the list. The rusting ground level is of grave concern. Are they? It is hard to tell from the description. W
As a practical matter, if the top bracket is 15 feet or less above the ground, it is probably not necessary to have a second bracket, so long as the tower is part of the concrete pour. Given the stif
Lag bolts into brick are not going to be sufficiently strong to hold a bracket. I estimated lateral forces in excess of 700 lbs in my bracketed installations. Carriage bolts are a must, and they must