Simulators

Drag the load, read off SWR and reflection, add coils, capacitors and lines, get an L network suggested and sweep across frequency. Plus a matching game with four levels.

Design low-pass, high-pass and band-pass filters: harmonic attenuation, parts as standard values, turns on the toroid and what each part can take at your power.

Rays through the ionosphere: change angle and frequency, read off hop distance, skip zone and MUF, with values from the nearest ionosonde and the elevation pattern of your antenna.

Send a step, pulse or carrier down sections of cable: reflections at joints and at the load, a TDR-style view, standing wave with voltage and current.

Noise figure, sensitivity and link budget stage by stage: rearrange preamp, LNB, cable and filter and see which stage sets the noise.

AM, SSB, FM, CW and FSK over time and in the spectrum: key clicks, overdriving, two-tone and IP3, plus the superhet's oscillator, image frequency and preselection.