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Configuring an antenna for (short distance) ground wave propagation on 40 m?

A dipole is not very portable, nor "small", if by that you mean, small area needed for deployment. A vertical, would be the most space efficient, requiring only one anchor point, 20M or so, ...
Louis Seaman's user avatar
  • 1,107
0 votes

Formulae for monopole antenna inductance/capacitance

In the application you describe, I strongly recommend a 1/4 wave monopole antenna. There's no benefit to a longer antenna, and there will be all sorts of pain trying to match it. It sounds like you ...
tomnexus's user avatar
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1 vote

Two different dipoles attached to three trees

It sounds like your trees are a little too close together. If you're going to be transmitting with these antennas, keep in mind that the ends of the dipole are high-impedance points — high voltage and ...
Dave Tweed N3AOA's user avatar
2 votes

Formulae for monopole antenna inductance/capacitance

As @Dereck points out, it would help to know about the device and your intended usage since it can determine the format of an antenna. @user98055, you say, "If I wanted to use a longer antenna (...
Louis Seaman's user avatar
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0 votes

Formulae for monopole antenna inductance/capacitance

get the ARRL Antenna Handbook until then try https://www.ece.mcmaster.ca/faculty/nikolova/ECE753_antennas.htm tldr. If you are not going for quarter wave, the next point to try to hit is just shy of ...
tomc's user avatar
  • 101
2 votes

Tuning a coil shortened 1/2 wave dipole for 80 meters

When tuning the dipole to acheive minimum SWR on my target frequency (3.900 MHz) where do I shorten or lengthen? After the coil? Before the coil (between the feedpoint and coil)? The easiest would be ...
Raonoke's user avatar
  • 151
0 votes

450-ohm ladder line fact vs fiction

Mike, allow me to take a shot at this. Not much theory, just some common-sense electrical facts. You do not want to run a ladder line near dirt or anything metallic. The ladder line is a Balanced ...
Dereck's user avatar
  • 565
3 votes
Accepted

450-ohm ladder line fact vs fiction

a repeated "consensus" is that the cable should be ... not on the ground or buried This is an accurate statement. Laying the cable on the ground, and especially burying it, is bad. The ...
Mike Waters's user avatar
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4 votes

450-ohm ladder line fact vs fiction

Here's some theory as to why this matters...keep this in mind and decide for yourself when you should worry. All transmission line (coax too, not just ladder line) works by forming opposing magnetic ...
user10489's user avatar
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