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As a rough rule of thumb, moving inductive loading from near the feed point to near halfway up an antenna of the same dimension might improve radiation resistance by somewhere around 2X, minus added resistive losses. But for antenna’s much shorter than lambda/4, radiation resistance goes up with roughly somewhere proportional to the square of the length. ...


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In an electrically short vertical, moving the loading higher is almost always an improvement because it raises the point of maximum current, where the majority of the radiation takes place. Center is better than base loading and top loading is superior to center loading. Top loading is usually accomplished by adding capacitance to the top, rather than ...


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Wire antenna are usually the easiest for beginners. The standard is a dipole with 1/4 wavelengths on each side connected in the center to your coax. Another easy antenna is a end fed half wave. It requires a bit more equipment as you need a transformer to match the high impedance. You can buy or make your antennas. Home brew antennas are a popular way to ...


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The cheapest antenna you can set up is a speaker wire dipole. A spool of speaker wire long enough to split the conductors and make a center fed half wave dipole ought to cost around ten dollars US (or less). You can get useful radiation with supports made from cheap stud lumber from the home improvement store (8-10 dollars per support to get 5 meters off ...


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Hello and welcome to the hobby! Generally speaking, it depends on your conditions and area available. Assuming it's not a problem (e.g. you live in a suburb area and have a backyard or are willing to travel to the nearest forest) the simplest, cheapest and quite efficient antenna you can build is a dipole / inverted-V. There are a few ways to build one. I ...


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I can think of two possibilities. The antenna and/or mast slipped 90° in relation to the rotor The rotator control box direction indication is 90° off. This could be caused by the pot in the rotor itself, or something inside the control in your shack.


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I would suggest that one of the transmission line connections to the antenna, probably the earth if you are using coax, has become disconnected at the antenna feed point, and it's just a coincidence that the SWR is still ok.


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Because you had a strong signal, I am thinking this is either a measurement error (clipping, for example) or a transmission error (high volume background noise, for example) of some sort. I will keep asking "dumb questions" in comments and update this answer as appropriate.


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Not an expert here, but since I don't see any answers yet these might be possible reasons: during the first leg of the trip, it seems like you had more or less line of sight. After that, there seem to be more buildings in between you and the base station. Maybe you had lots of reflections/multipath towards the receiver (the receiver receiving the signal not ...


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To add a partial answer to my own question, I realized I have at least one interesting test tool available, a tiny transmitter (TAPR WSPR board), controlled via a small computer (a Raspberry Pi Zero), smaller than the test antenna. Both can be run (for short periods) from a small battery, and the Pi can be either remotely controlled or run a timer-based CW ...


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By adding wire between the inductive and capacitive portions of a short but resonant antenna (while adjusting things to keep the natural oscillation frequency the same), will that wire radiate stored energy as well as energy supplied by the transmitter? That would be tricky, since the length of this wire would have non-zero length, and would be part of the ...


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By adding wire between the inductive and capacitive portions of a short but resonant antenna (while adjusting things to keep the natural oscillation frequency the same), will that wire radiate stored energy as well as energy supplied by the transmitter? Well, normally you don't have to add that wire, because you already have one and call it "the antenna", ...


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I've seen small devices that consist of a toroid with a few turns of wire around it and an LED, forming a loop wrapped on the toroid; these are slipped on the antenna and when transmitting, the LED lights where the antenna at the point where the toroid rests has RF current, with brightness proportional to the current. This device can then be slid along an ...


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A "resonator" may be used in a "resonant" circuit. A resonator is a circuit; resonance is a condition that exists at the natural frequency of the resonator. In order to resonate, a resonator, whether it contains "lumped" circuit elements (e.g, resistors, capacitors, inductors, etc.) or distributed circuit elements (e.g., transmission lines, antennas, etc.) ...


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The word Resonator is used to mean the loading coil in a short vertical whip antenna, that makes it resonate at the frequency of interest. The Hustler brand, for example, calls its coils resonators. I don't know or any other meaning of a resonator in antennas. I've never heard of it in a yagi or other "full size" antenna. I would use *resonant circuit" for ...


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First: do you know about pskreporter? You're definitely getting heard, including one spot on 40m from New Zealand. Sometimes FT8 takes some patience, and it seems like no one wants to come back to you for long periods of time, but pskreporter can at least provide some reassurance that your equipment and the ionosphere are actually in working order. That ...


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It looks to be a well done experiment. We see a sinusoidal current distribution in either case, and the current tapers off to (approximately) zero at the ends. But this is what we'd expect of any standing wave on a wire of this length. Where its fed doesn't matter. The problem with end-fed dipoles was never that they are impossible, but that they are ...


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I'm breaking your question into the two major parts within. Antenna system "When testing an amateur radio HF or VHF antenna, how would one absolutely minimize the amount of any RF radiation from the feedline..." I agree with Mike Waters about the judicious use of proper ferrites near the feedpoint and every 1/4 wave down the feedline to help quell any ...


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I am going to assume that you are using coaxial cable. In this case the problem is that the outer braid part of the cable is acting as part of your antenna. Here are 6 ways to do this. You can do one of them or combine them: wrap your coax into a big coil , probably at least 5 turns, very close to the antenna. This is sometimes called an "ugly balun" ...


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You have mixed up the characteristic impedance of a coaxial cable with the DC impedance measured from a piece of that cable. So I'll tell you what you measured and then what you could have done instead. First of all, I have no idea what does it mean to measure a capacitance with a multimeter when you have connected both measurement leads to the same piece ...


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