CW sounder solder project.

CW sounder soldering project, simple design using a 555 timer IC to make a CW sounder for scouts to try soldering, LED and adjustable tone

Designed to use a 9V battery, By changing R4 to a lower resistance, about 51Ω this circuit works great using 2 x AA PCB battery mount holder.

New board design, found the transistor was not required, and changed a few component values.

(Photo of the blue board above is the old design.)



The key is made by cutting off the RH strip and bolting to the board with a nut as a spacer and a small solder blob under the opposite end.

R1 - 330Ω Resistor.

Connected to the LED

R3 – 10k Resistor.

Tone adjust circuit.

Higher resistance = lower tone range

R4 - 51Ω Resistor if using a 3V Battery.

470Ω Resistor if using a 9V Battery.

Volume control. 20 Ω louder, 1K quiet.

C2 - Capacitor 0.1uf (104)

Changes the tone range 0.01uf

higher tone.