PK-4 - Ham Radio KITS - TOP PAGE

PK-4 Troubleshooting guide

Symptom: a PK-4 chip is plugged into a PK-3 or PK-Basic keyer socket, after powerup FB is heard, then the keyer sends a continuous stream of BE

Solution: add a 10 k ohm pullup resistor from pin 1 to pin 4 of the keyer socket.