There is something interesting afoot here. Look at the ads for trap antennas. There are precious few antennas which are rated more than 1500 watts PEP. Under the old rules for power output they used
What's wrong with your bridge? Show me the math that says this is so. de Brian/K3KO K I used only 1/4 wave of 90 ohm coax as that reached List Sponsored by AN Wireless: AN Wireless handles Rohn tower
This formula assumes a pure resistive load. You don't have that. Second, where does one get 90 ohm coax good for 1.5Kw? Third, it has always bothered me that you are not in my log after 40 years! I a
K7GCO. Wrong philosophy. Try the products first in the model and if it doesn't provide any improvment throw it in the trash. Your design first by prototype philosophy is not what any engineering firm
Those of you interested in a bit of history might try and find the MIT Radiation Lab book titled Transmission Lines, Antennas and Wave Guides. This book summarized the type of work done there during
Overheard on 40 meters SSB. "Something is wrong with your 160M antenna. Mine covers the whole band with a 2:1 or less SWR. Yours only has about 2:1 SWR bandwidth of 75 KHz" 73 de Brian/K3KO List Spon
K7GCO Here we go again. You have no credibility. You claim to have done all sorts of things when your were 5 years old in the 1930's. It is stupid to say we should build expensive prototypes today be
For those with aluminium towers, the magic stuff is aluminium sulfate. XYL uses it in the garden. It must be slow acting. Hasn't changed tower height yet. However, the temp change from the dead of wi
The "server" can't be found--either by clicking on first link or the second (and then clicking on file) de Brian/K3KO List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems, Trylon Tit
I have the driven element of a TH6 here. I want to press it into service for a 20/15 rotary dipole only. I want to somehow eliminate the 10 meter resonance of it to avoid coupling to other stuff on t
Guys, These links does not work for me. Even if I go to club page first and click on any of the links at the bottom the error message is the same: "server antennainfo" not found. This is with NETSCAP
Bill, As the original post said, the measurements were in wavelengths. So you have to first convert your boom length to wavelengths. Take the square root of that and then convert back to feet. It is
Guys, I'm fed up with using crummy RG59 to feed TV antenna. RG11 turns out to be even more lossy for the UHF channels. I have enough 1/2" or 3/4" CATV hardline to make the run. However, it appears to
This is wrong. Glenn Martin aluminium towers use 1200# stuff. They are nearly self-supporting to 60' and rated at 15+ sq ft at 86mph with the guys. They also use screw in anchors. The concrete base i
Guys, Thanks for all the info. Barking up the wrong tree. I think the task will be far easier if I use RG11 foam and the type f connectors for it that some say exist. One of the additional benefits I
Tom, I took the figures out of the 1993 ARRL handbook. They are for solid dielectric RG11. Foam is no doubt better. I believe your numbers. I keep hearing "are available". Where are the 3/4" hardline
Guys, Thanks for all your input. Have found some sources for what I need. I have really grown to hate type F connectors as much as I hate crimp connectors. 73 de Brian/K3KO List Sponsored by AN Wirel
Frank, My experience with this antenna is that it shifts hundreds of Khz from near ground to about 70 feet. The manual dimensions are quite close to the actuaal needed. Here they are: 72 3/4",44",44"
Hi Marc, Others looking at the same data concluded that your antenna is working properly at 28 M. I'm not so sure. One has to have some reasonable explanation of why the minimum SWR changed so much (
Marc, Just for kicks I ran EZNEC for a full sized 2 element beam (24' boom) at 24 and 28 M height. 24 M SWR =1.306 IMPEDANCE =38 -1.8j 28 M SWR =1.519 IMPEDANCE =33 -0.5j Interesting that the impedan