E. H. Armstrong
- Radio's premier inventor, Edwin H. Armstrong was responsible for the Regenerative Circuit (1912), the Superheterodyne Circuit (1918), the Superregenerative Circuit (1922) and the complete FM System (1933).
FDMDV - Digital Voice
- FDMDV - Frequency Division Multiplex Digital Voice
Digital Audio over HF SSB.
FDMDV is the latest digital voice mode on HF - it caters to high quality digital voice under poor band conditions, in only 1100Hz bandwidth
External Keypad for FT-817
- An external keypad for FT-817(ND), for the serious portable/field-day contester/operator. Homebrew it with the free firmware and public circuit diagram.
The circuit is very simple and takes power supply from the ACC port of the radio