A simple 2N2222 NPN transistor with a 1k-ohm resistor on the base works for modern rigs with low-voltage keying lines. C. The Audio Sidetone
The finalized schematic was converted into Gerber files and manufactured. k3ng keyer schematic repack
Use the repack as a visual checklist. Place components in order: power → microcontroller → LCD (if any) → paddles → key output. Test with a dummy load before connecting to a real transmitter. A simple 2N2222 NPN transistor with a 1k-ohm
The original schematics are often provided as individual EAGLE .sch files or fragmented PNGs, each tied to a specific hardware revision (e.g., v3.2, v4.0, v4.1). There is no single master diagram that shows all possibilities. Use the repack as a visual checklist
Don’t trust your memory. The repack should have a table correlating Arduino pin numbers to function. Cross-check this with the k3ng_keyer.ino configuration section (look for #define pin_dit and #define pin_dah ).
Thus, the holy grail of the K3NG repack isn't a static image. It is the —a Fritzing, KiCad, or even a DIYLC (DIY Layout Creator) project where you check boxes: