3/8" when I rebuilt mine. McMaster has several choices in stainless and steel. $10/100 for steel, from $26/100 for 440 to $50/100 for 316 (if you are really concerned about corrosion) stainless grade
You could scale the 20m "Field Day Special" by W7EL (EZNEC author) to 15m. Not exactly a "ZL Special", but very similar and a 50ohm feed. I built the 20m and it worked well and SWR was per the articl
Feeding the wire from the tractor is good if the pulls are really long, but then you need to build the puller. A simpler way is to cut each radial to length and pull from the antenna base with a simp
Paul, There are now three versions of the 40m Moxon by Dave Leeson, W6NL. The original XM240 (v1) mods, an strengthened XM240 "100 mph W6NL/Moxon for K3LR" (v2), and a scratch build "120 mph" (v3). K
Depends on what type of bearing - wheel bearing grease is made for roller bearings in constant rotation, not so good for ball bearings in oscillatory motion. A good full synthetic grease will not sep
A used boom lift might be a good alternative to building a tower. I've been tracking the used market and they go for $10k to $15k, used in good condition for 50-60 footers. (About the installed cost
a related conduit question - I noticed when checking out conduit at HD that the sch 80 sweeps are a larger radius than sch 40 at least in the 2 and 3 inch sizes they had laying around. So using sch 8
Good to know. Contrary to another response, sch 10, 20, 40, 80, 120, 160 etc pipes and pipe size PVC conduit (standard) all have the same OD, so any size will mate to any other size via a coupling or
On Line Metals stocks normalized (annealed) 4130 chrome-moly in the sizes you mention. Yield strength per ASTM should be 66,000 psi, which while not Grade 8 yield strength it is far superior (almost
I've had two verticals on metal roofs, old galvanized barn and shed roofs at that. A 80m hat loaded 40' vertical was terrific for DX, particularly when using a Beveridge or dipole for lower noise rec
My metal roofs are 2 miles direct line of sight to the towers of a 1 MHz 50kw AM station. Needless to say, that RF was everywhere and to measure any millivolt signals on my scopes I installed a good
Can some one share a pointer for up to date instructions for grabbing the terrain data from the web for HFTA? Every instruction I've found is hopelessly out of sync with the current terrain data web
For a 100' tower with EHS guys broken into non-resonant lengths, you will be putting 30+/- grips on, so buy some good gloves (maybe 2 pair) and be prepared for some sore hands. However, they are the
2.0 od into a 2.5 od with a nice slip fit means the 2.5 tube has 1/4 wall thickness! If these are your parts (it seems unlikely), you need a .25 wall 2" od internal splice tube. 0.058 wall isn't anyw
With the goal of shortening the rebuilt antenna, you might consider a Moxon derivative from your Al farm. Dave Leeson has published a mod to the Cushcraft 2L 40m (Visalia & Dayton 2004). I'm halfway
I'm building a new SteppIR beam and they have changed from tape wrapping the fiberglass element joints to an adhesive lined heat shrink "CANUSA CFTV". This approach seems better than two layer's of S
Harken or Ronstan or Lewmar - all are top quality sailboat pulleys - called blocks. The ball bearing ones are really good since the friction is significantly reduced. Bigger is better for the pulley
McMaster stocks Never-Seez in nickle only formulation, even "nuclear grade". See http://www.mcmaster.com/#never-seez-antiseize-lubricants/=e3634g Grant KZ1W __________________________________________
I'm converting a Force 12 180C 75/80m dipole from linear loading + relays to the Seco Tornado variable inductor at the feedpoint (a custom design) for full band coverage (85' long and EZNEC predicts
Not 8 tons load while I'm standing next to it! Think of the energy stored in the cable as it stretches and what happens if something breaks. Chain falls and chain lever units are much safer, since ve