What is so great about nonmetallic towers? I seem to be missing something here. They will not stop lightning and I suspect that if they are hit. And strong electric fields develop across any of the n
The Trojan Horse (BPL) A scaled down version of BPL is available at many computer stores right now. It comes in the from of special modems that use RF frequencies to allow a person to route relativel
At 12:00 PM 6/2/2004 -0400, towertalk-request@contesting.com wrote: I expect most antennas would fail by arcing limits for low duty cycle modes and by heating on high-duty modes like CW. The failure
You are probably right about the ground loss. In a balanced system the dominate loss will not be ground loss but you can't escape higher Q with short antennas. I'd prefer a vertical antenna with an a
A couple of years ago my department had to pay for the disposal of about 500 gallons of NON-PCB transformer oil removed from a 500KV power supply. It was transferred to new 55 gallon drums, tested an
Following are some links to information about "wire brush" static dissipators. It seems that cosmic rays produce the ionization trails that the static charge follows to produce lightning. You can't s
I have some questions, with some answers of my of my own. 1. Where does the charge come from that is being dissipated by the spiderball? Answer: From an induced charge on the ground that is balanced
Naturally their towers cost more but Heights Towers has very good documentation along with detailed up to date structural analysis of the towers. http://www.heightstowers.com/ 73 Bill wa4lav At 12:00
Gee, I have never broken a stainless steel bolt. They have been too hard. I have broken galvanized steel bolts. Particularly after they have rusted a bit. 73 Bill wa4lav At 01:30 PM 2/1/2005 -0500, y
Gee, I have never broken a stainless steel bolt. They have been too hard. I have broken galvanized steel bolts. Particularly after they have rusted a bit. 73 Bill wa4lav At 01:30 PM 2/1/2005 -0500, t
Why do you think the oldtimers used ceramic insulators on both the feedline and antenna? If matched and you have low loss feedline , a short dipole radiates just fine. But, the antenna systems Q will
Not the Rohn 45 or 55. The only towers that will withstand such high winds are ones designed specifically to do so. I was designing my Heights Tower to hold up to 125 MPH winds and constructed a spre
1. A quad is a compromise in a since because it is the same a 2 stacked shortened yagis with a separation of only 1/4 wavelength. It can be viewed as two 1/4 wavelength yagi driven or parasitic eleme
I believe it is simply capacitive coupling. 73 Bill wa4lav _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.
The problem in grain elevators is the static charge caused by the movement of grain from ground to the top of the elevator. Works just like a belt on VanDerGraff generator. And this relative small vo
If it reradiates noise why not reradiating the signal you want to receive as well thus S/N remains constant. How does the unused antenna know noise from signal? However, It can reradiate everything i
This is where the MBAs with the sharp red pencils go to work. Scratching out product lines that bring the least profit, have the subassemblies and circuit boards made in China and do the final assemb
I have. They are not cheap but built very strong and well designed. I am an engineer and was impressed by the amount of design information they have at their site. I wanted to make my tower taller an
This grease is simply a very pure silicone grease.It has no contaminates or hydrocarbons in it as does the cheaper silicone greases do. What makes is good for high vacuum should be good for connector
If you are talking about lightning damage the screen room will not help if you have a direct hit or very near one. With a direct hit on antenna or screen room most likely the screen wire will simply