I had the septic tank guy dig the hole for my tower when the house was built, and it came out perfect size and plumb sides. I guess digging septic tank holes is pretty close to the same thing. Jerry,
I looked thru my Tractor Supply catalog and the only thing I found that looked like it might work is the "3 and 4 Bolt Steel Flanges". If you can get the right hole diameter this might work. Page 202
-- I have asked this question on a couple of other reflectors and got no answer, so I will try this one also. Can anyone explain how putting a stainless steel shim between a copper wire and a zinc p
Those are some good questions. Others have addressed this with some limited success. W8JI uses a RDF technique for a figure of merit. This is convenient because EZNEC can give you all the data to cal
Good point. I never considered that he might be building a transmit antenna. I thought it was for receiving only. Jerry, K4SAV _______________________________________________ ________________________
The model included with EZNEC contains no wire losses, no transmission line losses, and no near field ground losses, and assumes average flat ground. Jerry, K4SAV ____________________________________
Something like an XM240 at 65 feet will easily beat a four square or a 3 element vertical. The take-off angle of the XM240 will be slightly higher than the 4 square, but the XM240 will have more gain
...."Is it because of some overvoltage issue on the shield? Maybe letting the coax be the sacrificial fuse (i.e. let it arc through the jacket) might be a good approach?"..... That is exactly what yo
Well you are thinking like a Californian. Direct strikes maybe rare in California, but in other places they are very common. I now live in a much lower lightning probability area than my Florida loca
My tower is only 55 feet, and 71 feet to the top of the mast, but it is also located on a hill and is the highest thing around for a long distance except for a very few trees about 700 feet away. NE
If you want to know why they are so loud, take a look at their website for a list of the equipment they are using. Also look at the site map. There is info on that map which they have not talked abou
Having the cables exit the tower above ground is a really bad idea. Voltage drop down the tower is very high during a strike. Anything exiting the tower above ground will see a very large voltage imp
If you just use di/dt for calculating voltage drops on lightning conductors you can get some very misleading answers. Sure if you have a known rise time and inductance you can calculate a voltage, bu
W6RMK wrote: Hmmm.. are we talking direct hits? The lightning literature is fairly full of the electrical properties of lightning strokes, and the current pulse typical stroke is substantially less t
I guess I didn't follow the explaination. Why would there not be a difference in torsional loading between a tower constrained only at the bottom versus one constrained at both the top and bottom? Je
It is interesting to compare Cebik's calculations for gain versus number of radials with that which W8JI measured. Cebik calculated that the gain difference between 4 radials and 64 radials was 1.2 d
-- Poor ground does make the difference larger, but to account for a gain difference of 5.5 dB in NEC, the ground quality at W8JI would have to be poorer that that in downtown New York City in the mi
I think you are a bit overloaded with that tower. The tower is rated for 16 sq ft at 70 mph and the MonstIR has a load of 23.9 sq ft. I'm not sure how the rating goes up as you lower the tower, but I
Are you sure you didn't get a metric number mixed in with the English numbers? Using Yaesu's method of figuring the K factor, I get 3264 ft-lbs for the antennas you have. The G-2800DXA is rated for 6