K3ng Keyer Schematic

The K3NG Keyer is a legendary open-source Morse code keyer project based on Arduino, designed by Anthony Good (K3NG). It is known for its massive feature set, including Winkeyer emulation, LCD support, and CW decoding. Core Hardware Components A basic K3NG build typically requires the following: HL2 and OpenCWKeyer K3NG Winkeyer - Google Groups

The K3NG CW Keyer 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

While there is no single "fixed" schematic due to the project's modularity, a basic build typically includes these key elements: K3NG Arduino-Based CW Keyer and Homebrew Paddles - kk9jef

The basement of the old radio club smelled of dust, rosin-core solder, and the distinct, sharp ozone tang of overheating components.

Elias wiped the sweat from his forehead with the back of his hand, leaving a smudge of grime. He squinted at the chaotic mess of wires sprawling across his workbench. He was trying to build a custom interface for his 1950s Hammarlund receiver, but his current straight key was murdering his wrist. He needed a memory keyer—something that could handle the repetition of contest calling without giving him carpal tunnel syndrome before the weekend was over.

"You're overthinking it," a gravelly voice rumbled from the shadows behind him.

Elias jumped, knocking a spool of hookup wire to the floor. It was Silas, the club’s resident curmudgeon and keeper of the arcane knowledge. Silas was holding a mug of coffee that looked indistinguishable from motor oil.

"I'm trying to get this paddle to interface with my linear amp without turning the rig into a doorstop," Elias sighed. "The timing circuits are a nightmare. I’ve burned through three 555 timers tonight."

Silas shuffled forward, his leather apron creaking. He peered at the schematic printout Elias had taped to the wall. It was a convoluted mess of logic gates and discrete components, drawn on the back of a pizza flyer.

"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."

"The what?"

"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."

Elias had heard of it in passing on the forums—a project by an operator named Anthony, K3NG. He had always assumed it was too complex, requiring a degree in computer science to understand. k3ng keyer schematic

"I'm a hardware guy, Silas," Elias said. "I like tubes and transistors. I don't want to write code."

"Then don't," Silas said, pulling a crumpled USB drive from his pocket. "The beauty of the K3NG schematic is the adaptability. You can build it as bare-bones or as elaborate as you want."

Silas plugged the drive into Elias’s dusty laptop. A file folder opened, revealing a massive collection of files.

"Look here," Silas pointed a calloused finger at the screen. "The schematic is designed around an Arduino, usually a Nano or a Mega. But see this section? It handles the paddle inputs. And this? The PTT (Push-To-Talk) output. It’s isolated. You won't fry your radio."

Elias leaned in. The schematic was surprisingly clean. It wasn't the chaotic spider-web he was used to. It showed a central microcontroller surrounded by support circuitry.

"It supports LCDs, PS2 keyboards, potentiometers for speed control... hell, it even speaks in Morse if you want it to," Silas explained. "But the core schematic is simple. You have inputs for your paddles, outputs for your rig, and a few resistors to keep things polite."

"Is that a win-keyer emulation?" Elias asked, his interest piqued as he traced the lines on the screen.

"Better," Silas nodded. "It’s open source. If you don't like how it sends a 'CQ', you change the code. But the schematic? That’s the map. You build the hardware right, and the software does the heavy lifting."

Elias looked at his pile of fried components. "I don't have an Arduino Nano."

"Check the third drawer," Silas said, jerking his thumb toward a filing cabinet.

Elias rummaged through the drawer, pushing aside ancient crystals and strange connectors, until his fingers brushed a small, blue circuit board. An Arduino Nano, still in its anti-static bag.

"The schematic lists a few specific components," Silas coached, walking back to the bench. "You need a 2N2222 or a 2N7000 transistor for the keying output—depending on if your rig wants a positive keying line or a ground. That’s the magic of the K3NG schematic. It warns you about the 'Winkey' compatibility and the voltage levels. It respects the radio." The K3NG Keyer is a legendary open-source Morse

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 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.

"Did you include the memory buttons?" Silas asked, looking over his shoulder.

"I added three," Elias said, pointing to three tactile switches. "One for 'CQ', one for my call sign, and one for '5NN TU'."

"Smart. Now, the code."

They compiled the firmware. Elias held his breath as the progress bar filled. Upload complete.

He plugged the paddle into the new box. He plugged the output cable into his transceiver. He powered on the rig.

Static filled the room.

"Give it a tap," Silas whispered.

Elias tapped the left paddle. A perfectly formed dit rang out through the speaker.

He tapped the right paddle. A smooth dah.

Then, he pressed the first memory button. Iambic A/B keying Straight key Paddle reversal Speed

“CQ CQ CQ DE K1ABC K”

The cadence was robotic perfection. The timing was flawless. No jitter, no wrist pain.

"It’s clean," Elias said, a grin spreading across his face. "The waveform is perfectly shaped. No clicks."

Silas picked up his coffee. "The K3NG schematic isn't just about making noise, Elias. It’s about offloading the tedious work to the machine so the operator can focus on the art. It’s a bridge between the heritage of Morse code and the modern world."

Elias looked at the small, unassuming device. It wasn't a mess of wires anymore; it was a tool. "I think I’m going to add the LCD screen next," he said, reaching for the schematic printout again. "I want to see the words as they're being sent."

Silas nodded, heading back toward the shadows. "Just mind the pin assignments," he called out. "And don't forget the pull-up resistors on the buttons. The schematic doesn't lie, kid. Trust the schematic."

Elias put his headphones on, listening to the rhythmic pulse of the band, ready to make contact. The schematic was no longer just a diagram; it was the key that opened the airwaves.

1. Overview of the K3NG Keyer

The K3NG Keyer is not a single fixed schematic but a modular design around an Arduino (Uno, Nano, Mega, Teensy, etc.).
It supports:

The schematic varies by Arduino board and features enabled, but a full-featured reference design is available on the K3NG GitHub repository (see k3ng_keyer_schematic.png and related files).

2.5 Speed Potentiometer

7. Function Buttons

Contest-ready K3NG schematics include buttons for:

These are wired as digital inputs with internal or external pull-down/up resistors. Usually, pressing the button connects the pin to ground (active low).

6. Display Interface (LCD/OLED)

For a full-featured keyer, the schematic includes a 16x2 LCD (using I2C to save pins) or a 128x64 OLED (I2C or SPI).

The schematic must pull up the I2C lines with 4.7kΩ resistors to 5V.

Common Mistakes and How the Schematic Prevents Them

Contact Us

Contact UsContact Us

WhatsApp