K3ng Keyer Schematic Repack

You’re operating 100W and the keyer locks up on transmit. A good repack includes RF mitigation strategies: shielded cables, RC snubbers on the key line, and proper grounding planes. The original schematic does not emphasize this.

The K3NG keyer supports 40+ pins of I/O. The original schematic treats the Arduino Mega as the center of the universe and wires everything in parallel. While functional, it’s hard to trace which pin does what when you’re looking at a single sheet with 15 off-page connectors.

The repack goal:

A critical missing piece in the original docs is the driver stage. The repack includes a standard NPN transistor (2N2222 or BS170) circuit to key the transceiver: k3ng keyer schematic repack

Many repacks also include an opto-isolator option (4N25 or PC817) for better isolation, with clear jumper settings for straight vs. Iambic modes.

You want: Iambic paddles, a 20x4 LCD, a rotary encoder, a PS2 keyboard, and a beacon timer. The original docs have pins scattered across three different pages. A repack will show all these devices on one page with a unified legend.

Some sellers who offer K3NG-based PCBs include a detailed assembly guide with a repacked schematic. These are often worth purchasing because the schematic is tested and known to work with the PCB. You’re operating 100W and the keyer locks up on transmit