~ Early Web Links ~

Electronics Notes, created and maintained by engineer Ian Poole, is a comprehensive reference hub covering electronics theory, circuit design, components, radio technology, antennas, ham radio, and more. With tutorials aimed at everyone from hobbyists to professionals, it also offers downloadable guides, infographics, and component data sheets, making it a genuinely useful destination for anyone working with electronics.

A comprehensive free electronics and electrical engineering reference hub covering everything from basic electricity and Ohm's Law to advanced RF design, DSP, amateur radio, and circuit simulation. With hundreds of curated links, formulas, tutorials, data sheets, and calculators organized across multiple phases of learning, it serves as a structured self-study guide for electronics enthusiasts and engineers alike.

Circuit Sage offers free design routines and tools for analog and RF circuit engineers, covering topics like PLL design, LNA/PA design, impedance matching, bandgap references, and transmission lines. The site provides Mathcad-based calculation routines that serve as practical references for IC and wireless circuit design work.

Tomi Engdahl's ePanorama.net is a vast electronics reference site covering audio circuits, video systems, PCB design, embedded systems, RF, and much more, with hundreds of categorized links and original schematics. The accompanying blog keeps the resource current with news, product tests, IoT coverage, and cleantech topics, making it a go-to hub for electronics hobbyists and engineers alike.

Robert Smathers maintains this personal hub dedicated to TVRO (Television Receive Only) satellite reception, featuring links, schedules, mail lists, newsgroups, and dealer resources for satellite hobbyists. The site also touches on visual satellite observing and space topics, making it a useful reference point for backyard dish enthusiasts.

Stavros Korokithakis documents his maker and DIY electronics projects, including building a custom $8 voice note recorder inspired by a discontinued pebble device. The blog blends technical tinkering with self-deprecating humor, making it an entertaining read for hobbyist electronics builders and software developers alike.

FC's Electronic Circuits is a sprawling hobbyist archive packed with schematics and project descriptions covering everything from solar charge controllers and LED circuits to tube amplifiers, Geiger counters, and amateur radio gear. With dozens of original circuit designs, Arduino projects, and links to related ham radio and electronics builders, this site is a goldmine for DIY electronics enthusiasts.

A technical reference site dedicated to RF chokes, ferrite cores, and related radio frequency electronics components used in amateur radio and RF engineering applications. Visitors will find practical information on choke design, impedance characteristics, and suppression of common-mode currents on antenna feedlines.

DiscoverCircuits.com, run by engineer Dave Johnson P.E., is a massive repository of over 45,000 free electronic circuits and schematics cross-referenced across 500+ categories for engineers, hobbyists, inventors, and students. Online since 2002, it serves as a go-to reference for quick design ideas, circuit solutions, and component resources covering an enormous breadth of electronic applications.

Peter's RF schematics page is a technical reference collection of radio frequency circuit diagrams spanning receivers, transmitters, and transceivers across a wide range of frequencies from 27MHz to 1GHz. Hobbyists and engineers will find schematics for superregenerative receivers, FM audio transmitters, walkie-talkies, SAW-based designs, and datasheets for chips from major manufacturers like Silicon Labs, HopeRF, and Texas Instruments.