At its heart, the K3NG keyer uses a microcontroller to monitor inputs (like your paddle or a command button) and control outputs (like your transmitter's key line or a sidetone speaker). Because it is open-source, the hardware design can scale from an ultra-simple minimal circuit to a highly complex workstation with displays and keyboards. Choosing Your Microcontroller
The Dit and Dash lines connect to individual digital I/O pins (commonly D2 and D5, though customizable in the code). The paddle's common ground connects to the Arduino GND.
: Full configuration and operation via a computer terminal. Core Architecture of the K3NG Schematic
The common ground of the paddle connects to the Arduino GND pin. 2. The Audio Sidetone Section
Many builders prefer using pre-designed PCBs that consolidate these features: K3NG - kk9jef k3ng keyer schematic
Many advanced K3NG schematics include a 1N4148 diode in reverse parallel across the transistor (Cathode to +V, Anode to Collector). This protects the transistor from the "flyback voltage" created by the relay coils inside older tube radios.
The K3NG keyer schematic is more of a "choose your own adventure" than a rigid blueprint. You can start with just an Arduino and a transistor and eventually scale up to a full-featured station controller with a display and memory buttons.
Requires 6 digital pins and a contrast pot, significantly cluttering the schematic. Stick to I2C whenever possible. PS/2 Keyboard Interface
Building one starts with understanding the . Whether you are building it on a breadboard or a custom PCB, 1. The Brain: Arduino Nano or Uno At its heart, the K3NG keyer uses a
The is a highly versatile, open-source Morse code keyer project based on the Arduino platform . Designed by Anthony Good (K3NG), it is widely regarded as one of the most feature-rich keyers available, rivaling expensive commercial units. Core Schematic Components
In the world of amateur radio, few open-source projects have achieved the cult status of the . Developed by Anthony Good (K3NG), this feature-rich CW (Continuous Wave) keyer has become the gold standard for homebrew station accessories. Whether you are building a simple portable paddle keyer or a fully automated contest station controller, understanding the K3NG keyer schematic is your first step toward mastering this versatile device.
Connects to Digital Pin 2 (Internal pull-up resistor enabled).
A is wired across the power rails. Pin 1 : Connected to +5V. Pin 2 (Wiper) : Connected to Analog Pin A0. Pin 3 : Connected to GND. Step-by-Step Hardware Wiring Matrix The paddle's common ground connects to the Arduino GND
Let’s explore each section as it appears in the standard schematic.
In the firmware, you map:
If you need help, the forum is an excellent resource. Many builders post their schematic variations there, and the project maintainer (Anthony Good, K3NG) is often present to answer questions.
