Antennas and RF
- Power, dB, dBm, dBi and dBd — what they mean Decibels as ratios, dBm/dBW as absolute levels, dBi/dBd as antenna gain, plus ERP and EIRP — with practical examples for radio amateurs.
- SWR without myths — what it says and what it does not SWR measures match, not antenna quality. Forward and reflected waves, VSWR, return loss, dummy-load counterexamples and cable-loss effects on readings.
- Antenna basics — wavelength, resonance and SWR An amateur-radio intro to antennas: wavelength, resonance, polarisation, gain, radiation pattern, feedline, impedance, SWR, height and location.