He placed the Nano at the center. He soldered the paddle inputs to digital pins D2 and D3, exactly as the schematic dictated. He added the speed potentiometer to the analog pin. He carefully constructed the output stage, using a 2N2222 transistor to key the transmitter, his movements guided by the precise lines of the K3NG diagram.
The K3NG firmware usually enables the Arduino’s internal pull-up resistors. This means you simply wire the paddle to ground. When you press the paddle, it pulls the pin "Low," triggering the code. k3ng keyer schematic
"Rube Goldberg would be proud," Silas grunted. "But if you want elegance, you don't need a bucket of logic chips. You need the K3NG." He placed the Nano at the center
For the next three hours, the basement was silent except for the hum of the soldering iron and the soft click of components snapping into a breadboard. Elias stopped fighting the circuit and started following the roadmap. He carefully constructed the output stage, using a
"The K3NG Keyer," Silas said, setting his coffee down on a stack of QST magazines. "Open-source. The holy grail of the modern shack. It’s not just a schematic, kid; it’s a philosophy."
The solves this with a 2N2222A transistor (or BS170 MOSFET) and a 1kΩ base resistor .
Grab an Arduino, some transistors, a few resistors, and a soldering iron. Download the schematic. Start prototyping. Within an afternoon, you’ll be sending perfect CW—knowing exactly how every dit and dah flows from paddle to radio.