Tom, I haven't seen Dr. Best's article or even read Maxwell's book for that matter, so I am coming somewhat from a point of ignorance. My questions is, are the graphs that you see in the ARRL handboo
I have a heavy duty pulley (1300 lbs working load) here that I was thinking of using as part of a tram for an upcoming tower project. My plan was to possiblly attach this pulley to the antenna mast a
The following is summary of replies that I received to my inquiry about gin pole strength. Thanks to all who replied - the information is greatly appreciated. 73 de Mike, W4EF................. Can an
Does anyone know how to get hold of KLM. Their web site no longer responds. I need some spare parts for a KT34XA and a 40 meter 4 el big stick. Thanks, Mike, W4EF................... -- FAQ on WWW: ht
I did some topband operating in the CQ WW 160 contest this past weekend courtesy of an invite from Paul, N6LL to his sight on Mt Wilson, Ca. The sight which overlooks the L.A. Basin, consists of seve
Does anyone sell a good (corrosion resistant) SO-239 to wire pigtail adapter? I am looking for a clean way to transition from RG-142 (common mode choke balun) to the screw terminals on a 155BA. BTW,
Very interesting, Kurt. I wonder if Sharpies are safe? These things are great for marking on just about anything, but I never thought about the corrosion angle. 73 & HNY, Mike, W4EF.............. --
Dick, If you have a good 50 ohm termination, put it at the end of the coax run and measure the input return loss of the system as a function of frequency. I think you will find that the "anomalies" i
This probably falls into the category of how do I find true north and what does VSWR stand for, but I need opinions on mounting a T2X in Rohn 25G. Our new mast will be 24' of 2" O.D. 4130 chrome moly
Mark, The wind load capacity of the tower should be similar to 34' of freestanding Rohn 45G. According to the Rohn catalog, 100' of Rohn 45 bracketed at 33' and 66' provides a 70 MPH wind load capaci
Hi Pete, I am working up a spread sheet for a similar problem. My quick and dirty back of the napkin spread sheet says that the Rohn 25 should be okay in terms of bending moment with the parameters y
Hi Steve, I was thinking about this problem a little more this morning. The force that gets transmitted to the rotator depends a lot on how much slop there is in the top tube, how much "give" there i
Hi Steve, I was thinking about this problem a little more this morning. The force that gets transmitted to the rotator depends a lot on how much slop there is in the top tube, how much "give" there i
Gerry, Even without the TH-11DX on top, a 72 foot tower should look like at leat a 1/4 lambda on 80 meters. With the antenna installed, my guess is that the structure will be resonant somewhere aroun
Our club has a KT34XA /40 Meter 4 element stack which will be coming down later this year as a result of some scheduled tower repair (new rotator/mast/tower section). This will be a good time to clea
Tom, When you refer to displacement current due to the weak electric field, are you refering to the electric field between the side of the doublet driven by the center conductor of the coax and the b
Dimitry, et al: Just a quick comment, the ultimate strength of a mast is not as simple as the cross sectional area times the yield strength. The ultimate strength also depends on the shape of the mas
Dimitry, et al: Just a quick comment, the ultimate strength of a mast is not as simple as the cross sectional area times the yield strength. The ultimate strength also depends on the shape of the mas
David, This question is not as absurd as you might think. First of all, I think people are confusing two issues, bending strength and damping. Filling an antenna element with some "stuff" to dampen a
I am looking for an epoxy suitable for use in a high power RF switch application. I need to keep the center conductor of an SO-239 from rotating. Does JB Weld have suitable properties as an RF dielec