RadioHistory & Technology
From Hertz's pioneering experiments through Tesla's first radio patent to modern digital broadcasting, explore 130+ years of wireless communication history.
Radio Topics
Navigate through the topics and technology of radio
Radio History
From spark gap to software-defined radio — 130+ years of wireless communication
Nikola Tesla
The true inventor of radio — filed the first radio patent in 1895
Early Radio History
Maxwell, Hertz, Tesla, and the birth of wireless communication
Heinrich Hertz
Proved Maxwell's equations and the existence of electromagnetic waves
Guglielmo Marconi
Commercialized wireless telegraphy — built on Tesla's prior work
Radio Broadcasting
The golden age of radio entertainment and the birth of mass media
FM Radio
Edwin Armstrong's frequency modulation and stereo broadcasting
Amateur Radio (Ham)
Ham radio hobby, emergency communications, and technical experimentation
Maritime Radio
Ship-to-shore communications, GMDSS, DSC, EPIRB
Digital Radio
DAB, HD Radio, DRM, and modern digital broadcasting
CB Radio
Citizens Band — 40 channels, AM/SSB/FM, antenna design
Car Radio
From Kelly's Motors (1924) to DAB+ and diversity antennas — radio reception in a moving metal box
Spread Spectrum
DSSS, FHSS, CDMA — how spread spectrum enables modern wireless
TETRA
Terrestrial Trunked Radio — TDMA, π/4-DQPSK, public safety
Packet Radio
AX.25 protocol, KISS TNC, amateur digital communication
Shortwave Broadcasting
3-30 MHz skywave propagation, international broadcasting, numbers stations
Longwave Broadcasting
148.5-283.5 kHz — European LW stations, DCF77, NDB beacons, antenna engineering
AM: Amplitude Modulation
Mediumwave/AM broadcast theory, transmitter classes, antenna design, DXing
Spark Gap
The first radio transmitters — damped wave generation and early wireless
Amateur Radio Satellites
Radio amateurs built and launched the first civilian satellites — OSCAR and beyond
Superheterodyne Receiver
The dominant radio receiver architecture — IF mixing, image rejection, AGC
Antenna Theory
Isotropic radiators, gain, polarization, Yagi-Uda, log-periodic, antenna fundamentals
Impedance Matching
Transmission line theory, stub tuners, baluns, and maximizing power transfer in RF systems
Crystal Radio
The foxhole radio, galena detector, and receiving radio without any power source
Pirate Radio
Offshore broadcasting, Free Radio, Radio Caroline, and broadcast regulation