Champion Radio provides the data by US county - see http://www.championradio.com/windspeed-data.php?abv=&county= Grant KZ1W _______________________________________________ ___________________________
Although I am not an expert in these matters, it appears that ASCE 7-05 is the (current??) reference document for structural calcs. Various file sharing sites have parts of it, but I did find what ap
You don't mention the ear orientations but if you tilted the tower up on installation one would think the matched pair of ears are away from the house and the single is towards the house. I assume th
Correction - for the tower to tilt (at least the Tri-Ex and USTs I have), some spacer plates the thickness of the ears on the foundation are needed between the riser plates and the tower ears, since
Last week I built the fan dipole from http://www.hamuniverse.com/multidipole.html for 80/40/20, figuring I would use the 40 on 15. I used 3/8" square 4' long PVC gray rod (McMaster) cut to 3'+ long t
I had one of these elevated resistors briefly in 1980. It was very very quiet at both ends. Might be ok for quick GOTA, emergency, or NVIS, that's what it seems the military wanted it for. Grant KZ1W
I have the larger Harbor Freight mixer and would not recommend the investment. The drum drive is poor, the Chinese motor is weak, it doesn't mix well unless the dry mix is added incrementally, the sm
I built the "Field Day Special" (by W7EL) 20m antenna which uses 330pf 500vdc silver mica capacitors in each lead at the feedpoint to match 50ohm coax. It seems to work fine, so now I'd like to upgra
I had nine 36" diameter by 8' deep holes bored for 24' x 8" pipes to hold PV panels. County said it had to be so. The contractor used a Bobcat with hydraulic auger, a pretty impressive rig for diggin
Your "problem" (not sure you have one) is the difference in stretch of the Phillystran vs EHS. Adding more tension to the Philly helps that a bit, but at the cost of a lot more column load on the tow
One factor not mentioned is that it is unlikely a significant moment can be transmitted by the two plates in contact. One side of the plate will lift as soon as the base moment exceeds the downforce
My I.C.E. coax arrestors measure 680k to ground on the radio side. It seems like a good strategy to bleed off static with a high value non-inductive resistor. 10x that amount (6.8Meg) would handle 25
Good question. I should have said "carbon comp" instead of "non-inductive". Carbon film and metal film resistors will degrade/fail with high surge currents. Carbon composition resistors have a higher
Bases have gotten bigger. Crankup mounting plates have much heavier steel and angles rather than plates. The catalogs show much less concrete than the actual wet stamped drawings I have for my HDX589
I understand the wisdom of not burying bare aluminum shield hardline. Is there a concern with the PVC covered versions? Any difference with Heliax copper shield? (can't get Heliax wrong, I hope). Are
The TVI was most likely an arc or spark when the voltage exceeded the breakdown voltage of the oil film in the bearing. race - oil -ball -oil - race. So the rotator halves are insulated from each oth
Unless the ground is very soft, the copper pipe will mushroom and not drive in, so a regular ground rod is the way to go as Jim mentioned. For SDS and spline hammer/chipper drills (e.g. Bosch), you c
I bought some standard ones from the US distributor but can't find their name. The complete catalog, in Japanese, is at http://us.100y.com.tw/pdf_file/10-NCS.pdf; it shows an angle version NCS-256-LP
Aha - one more page and there it was http://www.kineticllc.com/catalog.asp?prodid=672201&showprevnext=1 $9.00 for the standard, nice folks, don't know if they can get the angle one. Grant KZ1W ______
Vishay makes Transient Voltage Suppressors (TVS) in clamp voltages from 10 volts to several hundred volts. A common size can handle a 1500 watt surge. They are very fast, I think faster than MOVs and