RUNSLINUX / RADIO

Radio Learning Lab

Listen, experiment, and build confidence—one signal at a time.

Know what you are hearing

AM & FM

AM changes a carrier’s amplitude. FM changes its frequency. Choosing the wrong receiver mode can make an otherwise strong signal hard to understand.

SSB

Single-sideband voice uses less spectrum than ordinary AM. USB and LSB select opposite sidebands. Precise tuning matters.

CW

Keyed carrier pulses represent Morse characters. The receiver produces an audible tone so you can distinguish dots, dashes, and spacing.

Digital signals

Computer-generated tones can carry text and data. FT8, RTTY, and packet are different protocols; hearing tones alone does not identify or decode one.

Morse practice

Type a short message, hear it as CW, then try a listening challenge. Audio starts only when you press Play.

Ready. Use headphones or a comfortable speaker volume.

Morse reference

Antenna workbench

Starting dimensions for a wire dipole or quarter-wave element. Real antennas require trimming and measurement; nearby objects and wire construction change resonance.

Free-space wavelength = c / f. Corrected half-wave dipole = wavelength × factor ÷ 2. A quarter-wave element may need a ground plane and is not an entire antenna system.

Find a Maidenhead grid square

Convert coordinates to a six-character amateur radio locator. This runs in your browser; coordinates are not sent to our server or saved.

The starting point is central Tulsa, not a station or home address.

Quick knowledge check

Keep learning

Practice tools here generate audio locally. They do not transmit RF or control the receiver.