Miniature CW keyer (elbug) OH2NLT

1206 size pcb added 29.01.2006


Very small CW keyer designed for to use with JUMA-TX1 transmitter. Keyer can also be used with other transmitters. Open collector or active 0-5V TX drive is provided. Miniature speaker can also be connected to the circuit. Speed is controlled with 100k potentiometer. If speed range need to be adjusted it can be done by changing C2 value. Keyer is implemented with Microchip PIC10F206 6-pin SOT-23 controller. Keyer has two operating modes. Default is Iambic type. Other is so called Golden Key mode where period (DI) has precedence if both keys are pressed simultaneously. Golden key mode is selected if left key (DI) is kept pressed during power up. PIC10F206 is also available in DIP-8 package, which is handy for breadboard construction. See pictures and note different pin out for DIP-8 package. Keyer is suitable for QRP rigs because of low power consumption. Standby current is only 500uA and max operating current about 4mA.


Project with 1206 size components. 1206 size match with other JUMA components.

Schematics (1206)

PCB artwork 1:1(1206)

Component placement(1206)

Part list


Project with 0805 size components


PCB artwork 1:1 | self made PCBs with this artwork

Component placement 2:1



Software v1.00, Iambic & Golden Key

Software v1.01 more modes added. Straight and "Vibroplex mode" See software comments for details.


Keyer assembled. Component side | back side


Keyer installed inside JUMA-TX1 transmitter. Note ! 5V for keyer taken from DDS board.

TX1 back panel

JUMA-line station


Prototype with DIP-8 IC. Picture 1 | Picture 2 | Picture 3

Paddle in the pictures