When I put up my tower in 1989, I used 3/16" EHS and big grips. At the time, I don't think anything was normally placed at the end of the big grip. Just to be safe, I put a 3/8 inch cable clamp at th
Nylon is notorious for degrading very fast in sunlight, so don't use it for antennas. Dacron/polyester is much, much better. Some line has a nylon core and a polyester sheath, which seems to work fin
When I last put my TH7 up in 1993, I put a drop of blue Loctite thread adhesive on every fastener, except the hose clamps on the elements. Before I took it down last week, nothing had moved. (It stil
I'm replacing my old Rohn 25 with the same. Because the embedded base section is rusting, I'll just drill a hole in the concrete and install a pier pin. I have three questions: 1. What kind of adhesi
Hi Pete, I'd be concerned that the metal to metal contact might invite IMD or generation of harmonics. 73, Scott K9MA On 4/30/2019 14:17, N4ZR wrote: 73, Pete N4ZR Check out the Reverse Beacon Networ
Just be sure the wire can slip off the sheave and get jammed in the gap. Another possibility: Solder little loops of wire onto the antenna a few feet on either side of the pulley and tie a piece of r
After nearly 30 years of holding up my TH7 and D40, the thrust bearing was pretty rough. The T2X never had any trouble turning it, but I took it apart to see what was going on. I found the surfaces o
True, but the rotator distributes the load among a much larger number of ball bearings. The shape of the races in the TB3 make it clear it was designed primarily for radial loads, not axial. Also, a
The TB3 did last for almost 30 years. 73, Scott K9MA Grant KZ1W Your post brings up some important points. First, when using any thrust bearing (TB), it is important to realize that the TB may not be
As my tower replacement project progresses, I opened up the rotator. It was working normally before I took it down a few weeks ago, though it sounded a bit rough. Inside, though, I found some serious
test -- Scott K9MA k9ma@sdellington.us _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.con
I like the system used on the W3JK antenna I'm building right now. It uses hex head machine screws with nylock nuts (UV-proof). The hole in one side of the outer section is drilled larger, so the sc
Not hex head screws. Socket head (Allen) cap screws instead. Outside perimeter of head is round. Big difference. Sorry, socket head hex screws. 73, Scott K9MA -- Scott K9MA k9ma@sdellington.us ______
The last time I worked on the A3, I found that the hose clamps just wouldn't hold the tubing securely enough that I couldn't easily move it, so I added the sheet metal screws. (The hose clamps did s
Ah, the poor man's 4-wire ohmmeter. That would be about 0.4 V at 20 A. If it's copper. Or, you could weigh a length of it an do some arithmetic. I suppose that might not rule out a high resistivity
NEC3 doesn't model closely spaced wires well, so it may not work for the matching system. NEC4 should work. Another way, which should work with NEC3, is to model the feed assembly as a transmission l
Does anyone know where to find the article, in QST, I think, about this topic? (I've searched the QST archives on every keyword I can think of.) Failing that, any other source of information? My guy
The 520 pound result is correct. 73, Scott K9MA For example. with the lifting point at 10 feet from the fixed or pivoting end of the 40ft tower and a 50 lb load at the very end of the tower, 30 ft fr
FWIW, Im about halfway through excavating my anchor rods, buried in 1989. The zinc is gone and theyre rusty, but so far no significant reduction in diameter. If I can just find the galvanic stuff in