Good questions Jim. I called the tube supplier and they told me the tube is stress relieved but not quenched as in traditional heat treatment. The 'SR' designation in the description denotes stress
FYI. I got the answer from the American Galvanizers Association. Very short and direct. No, only when you get to 150 ksi do you worry about embrittlement. No change to strength. Philip G. Rahrig, E
Hi Larry, I ran into the same dilemma and I came up with a very simple solution. The solution will remove about 44' of cable 'slack'. The end result is that only about 10' of cable actually touches
When the wind picks up to, say 40mph, I leave the tower halfway retracted. The loop just hangs in the air without touching the ground and it sways in the wind harmlessly. If a major windstrom comes
Hi All, I made a Youtube video of my coax cable management system. Most of the coax is hanging in the air out of harm's way. Only the last five feet of coax touches the ground. I welcome any criti
Hi Jon, et al. Thank you for the nice comments. Just to add two more things, It's better to use a Kellem cable grip for the 180 degree cable turn. Currently I'm using hose clamps but the Kellems ar
Hi All, I'm having a problem where one of the cadweld one-shot doesn't have any of the igniting powder in it. From what I've gathered the main powder material needs a very high temperature to ignite
Hi All, Thanks for all the replies on and off the list. Now I have a better understanding of what thermite is. I've decided not to experiment with chemistry time. 73. Best Regards, Jonathan Woo,
I understand all the rave about trapless antennas. I have one too, a trapless tribander with 3 elements on 20m, 3 elements on 15m, and 4 elements on 10m. And I have purchased Steve's comparison rep
Regarding failure points: I've seen photos of two fallen US Tower retractable towers and both of them failed at the very bottom. The problem with designing a retractable tower such that it will fail
Lots of good discussions here. I want to bring up a few points. - Regarding crank up tower one should run two sets of stress calculations, one for the fully extended position and one for the fully r
I'm not an engineer by profession; so I'm not saying that this is correct. In various software programs and Excel spreadsheets I obtained from ham-related sources use a Cd of 1.2 for round members a
Hi Folks, I'm about to purchase a rotatable dipole for the WARC bands. I already have two yagis up on the same mast. I don't know where to put this dipole and at what orientation (parallel to the y
Hi All, I'm new to antenna modeling and I have lots of questions. I looked for a user group for EZNEC but couldn't find one. So I created a group to help me and many others who share a common inter
Hi Rick, No, I didn't see this one. I did ask two hams who use EZNEC and neither one told me about this list. Thank you for bringing it to my attention. I will join the list. I did find a group on
Hi Jim, Sorry for wasting the bandwidth but I feel obligated to provide you with some facts. I have the Antenna Modeling book by Ward Silver, the ARRL antenna handbook, and the EZNEC manual. I ran