All this grounding talk has got me thinking again. Most of us know that the impedance of a wire is increased by its skin resistance, and that a wire with more skin area (such as a strap) will provide
Given that a 0.5 inch wide strap is about the same as a wire.. what about multiple wires in parallel.. If they are spaced apart far enough, the inductances will be parallel. -- Good thought, but thi
Jim Lux wrote: ..."Hmm.. but, if I had four AWG 10 wires laying side by side, that's like a 0.4 inch wide by 0.1 inch high strap... i.e. the L should be 0.40 uH (give or take) for the 10 foot run. I
The biggest problem you have with low band multiple L antennas is matching and bandwidth. To start with, a 160 meter L will not have a lot of bandwidth and the impedance will be low compared to 50 oh
You two guys don't seem to be communicating because you are both correct (neglecting a few misworded comments). Currents traveling down a tower will be partly shared by the coax. How much is question
AAARG! I hate it when this happens. My table of wire impedances has an error. The formula had a decimal point error. Plus the strap inductance calculations has the same decimal point error. I found i
..."Here we go again... so which is it? Inverted L's have plenty of bandwidth or Inverted L's little bandwidth??? "... The traditional L with a good ground doesn't have much bandwidth. But WA3AFS doe
This is about the fourth time I have posted this message in response to the same question. But no problem, I saved it. I'll just dump it again. For some free software to make these calculations go to
I am not familiar with all the limitations of MMANA, since I mainly use EZNEC. However, the procedure would be to include the towers into the model. Use segments that approximate the diameter of the
For your 1 day option of running an 80 meter dipole on 160, here is a piece of data for you. Assuming an antenna height of 50 ft, if you are feeding the dipole with 100 ft of RG8X, loss in the coax o
Most people on this reflector are used to thinking in terms of grounding towers, not dipoles. The same rules apply to dipoles, but there is another problem with dipoles that puts it into the hard pil
..."If the Feedline is #12 or larger copper, it will carry the current of 90% of strikes and will fail open in the rest."... -- If you believe this, you haven't seen many lightning strikes. If a #12
Be careful when using HFTA to model stacks. HFTA does not model antenna interaction. All rays are assumed to go outward from the antenna between 0 and 34 degrees elevation. No rays directed upward at
I need to correct a couple of statement I made about HFTA. I said HFTA always gives 3 dB gain for any antenna stacking distance. That is not correct. It gives 3 dB gain for very closely stacked anten
Looks like you have a pretty tall order there. As I calculate it, you have about 20 sq ft of antennas to put on a single mast. Without considering as to whether the antennas will operate properly or
Oops, when calculating those numbers, I had the mast thickness set at 0.12 (didn't notice it). I should have used 0.25. With 0.25 thickness, antennas at 2 ft, 10 ft, and 17 ft would require a materia
Right Dan. Obvious typo. Thanks. Jerry _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.con
They are very simple as you expected. The design process is straight forward. It's just a capacitor in series with the coax line, and an inductor connected to the center line, and on the other end of