7

The advantage of Litz wire —lower loss than solid wire— is realized below about 1 MHz. It is of little use above 160 meters. From https://en.m.wikipedia.org/wiki/Litz_wire Litz wire is a particular type of multistrand wire or cable used in electronics to carry alternating current (AC) at radio frequencies. The wire is designed to reduce the skin effect and ...


4

Small loops and full-wave loops are very different antennas. There isn't a well-defined distinction between "small loops" and "large loops", but a typical rule of thumb is a loop is "small" when its diameter is less than 1/10th of a wavelength. At such a size, the phase delay around the loop is negligible and thus the current ...


3

When tuning can be achieved then the only variables you have to optimize is the coupling and the compensation of the feed loop inductance (because k < 1). Just modify the area of the feed loop by bending the wires to a smaller or a larger area. You will end-up close to 50 Ohm. But resonance of the loop does not exactly correspond with lowest impedance. ...


3

When I connect the probe from my oscilloscope, does the probe also act as an antenna? As it appears in your photo, yes. In some applications this may not matter, but in your case it sounds like your experiment relies on the loop having a predictable pattern for direction finding. In this case, having the probe (and also the scope chassis, and its power cord)...


2

Partial answer to part 1 of your question. Yes, the loop created by the open space between the ground lead of your scope probe and the probe tip acts as a small (parasitic) loop antenna. But mostly for wavelengths much shorter than 1/10th the diameter of the loop (potentially caused by the rising and falling edges of a spark). If you are just testing ...


2

Well put, Phil. According to a simulation comparing a 1-turn full-wave loop to 2-turns of the same loop, the radiation pattern is the same while the feedpoint impedance increases by a factor of four: These values are for an antenna less than a half-wave above the ground. Raising it to a half-wave above ground does move the maximum radiation to lower angles, ...


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