For a VLF receiving loop, the exact wire length is usually far less critical than people expect. At VLF (about 3–30 kHz): So you are not building a resonant half-wave…
Success with detection! Bits and pieces arrived to make new aerial – and attached are test screenshots from Spectrum Lab – 6 stations seen clearly. This time, for some reason,…
Absolute workhorse of RF switching. WHAT IS A PIN DIODE? A PIN diode is a semiconductor diode with three layers: The middle layer is a thick, undoped (intrinsic) region. That…
WHAT IS A DICKE SWITCH? A Dicke switch is a rapid RF switch used in radio astronomy to reduce receiver gain drift. It switches quickly between: This technique was invented…
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The skin depth (δ) of RF in copper at 1420 MHz can be calculated using the formula: δ = √(2/(ωμσ)) Where: At f = 1420 MHz (the hydrogen line frequency):…
Since you’re building a tuneable waveguide probe (I’m assuming 1420 MHz given your past adventures…), here’s a clean, mechanically stable way to do it without it turning into a wobbly…
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Loss is a length multiplier, so a 200 ft length would have twice the loss shown above and a 50 ft length would have half the loss. This multiplier factor…
There isn’t a single magic thickness that by itself gives 50 Ω — but in practice, for standard rectangular waveguide probe feeds, there is a very reliable working range that…
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