For doing something with what the shops sell: where to have boards and chips made, where to find what a part is, and where to ask.
printed circuit boards
Prototype boards from a design file, in small numbers; most will also put the parts on.
| JLCPCB | China | boards, assembly, stencils |
| PCBWay | China | boards, assembly, and machining and 3D printing besides |
| OSH Park | US | purple boards made in the US, shared panels for small orders |
| Aisler | Europe | boards, stencils and assembly, made in Europe |
| Eurocircuits | Belgium | boards and assembly |
| Seeed Fusion | China | boards and assembly |
| OSH Stencils | US | solder paste stencils |
your own chip
A design of your own on real silicon, shared with others' on one wafer to keep it affordable.
| Tiny Tapeout | a small design on a shared chip, with a board to try it on; a way in for beginners | |
| wafer.space | budget silicon manufacturing |
metal, panels and enclosures
The box and the front panel, cut or machined from a drawing.
| Front Panel Express | US | engraved and machined front panels and enclosures |
| SendCutSend | US | laser and waterjet cut sheet metal, bent and finished |
| Ponoko | US | laser cut parts in metal, acrylic and wood |
| Xometry | US | machining, sheet metal, molding and 3D printing, by quote |
datasheets, manuals and tube data
What a surplus part is and how to use it, and the manuals for old equipment.
| Datasheet Archive | datasheets, many for long-gone parts | |
| alldatasheet | datasheets | |
| SMD codes | what the few letters printed on a tiny part mean | |
| Frank's Electron Tube Pages | tube datasheets, scanned | |
| Radiomuseum | old radios and tubes: data, schematics, a forum | |
| KO4BB | test equipment manuals | |
| Bitsavers | manuals and software for old computers | |
| Elektrotanya | service manuals and schematics | |
| World Radio History | old electronics and radio magazines, scanned |
design and simulation
Free tools to draw the schematic and the board, try the circuit, and design the case.
| KiCad | schematics and boards; the boards above take its files | |
| LTspice | circuit simulation | |
| ngspice | circuit simulation, open source | |
| Falstad circuit simulator | a circuit running in the browser, to watch and play with | |
| FreeCAD | 3D design, for enclosures and parts |
where to ask
People who know, and the projects others made.
| EEVblog forum | electronics, test equipment, repair | |
| r/AskElectronics | questions about circuits and parts | |
| Antique Radio Forums | old radios and their restoration | |
| Hackaday.io | projects others built, with their parts and files |