Screwdriver Antenna: A Motorized Tunable Vertical for HF
Screwdriver antenna guide: how a motor-driven coil tunes a short vertical across HF bands, what efficiency and bandwidth to expect and how…
Read more →Screwdriver antenna guide: how a motor-driven coil tunes a short vertical across HF bands, what efficiency and bandwidth to expect and how…
Read more →Repeater duplexer explained: how cavity filters let one antenna transmit and receive at once, what isolation and offset mean, and why tuning…
Read more →Hardline coax gives the lowest loss for long VHF, UHF and microwave runs. Learn the types, sizes, connectors, bend limits and when…
Read more →Crystal ladder filter guide: how identical crystals and shunt capacitors make a narrow IF filter, how to match crystals, set bandwidth and…
Read more →How the PSK Reporter live feed in DX Reminder works: why reports used to arrive late, what the MQTT link changes and…
Read more →An RF burn can come from touching an antenna, a tuner or a microphone while transmitting. Learn how it happens, how to…
Read more →Direct conversion receiver explained: a mixer at the signal frequency makes audio directly. See why it is easy to build and what…
Read more →PLL synthesizer and DDS compared: how a radio generates a stable tunable frequency, what step size and phase noise mean, and where…
Read more →Direct burial coax and conduit compared: which cable jackets survive in the ground, how deep to dig, how to seal the ends…
Read more →Make the DX Reminder alarm ring on a silent phone: notifications, Alarms and reminders, battery saving, full-screen alarms and your own alarm…
Read more →A diplexer lets two bands share one coax: how the low-pass and high-pass pair works, isolation, insertion loss, power limits and how…
Read more →Solar eclipse and ham radio: how the Moon's shadow changes the D, E and F layers, which HF bands improve or fade,…
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