Morse code test oscillator

Simple Morse code test oscillator for Morse practice – A Simple (& cheap) soldering project


I designed this for a Scout group as a simple soldering project Electronics Badge and as part of the Communication Badge.

With care the parts can be sourced for under £2.50 each.

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The boards can be ordered from OSH Park and cost £2.20 for 3
Order from OSH Park





1 x 3mm Led
1 x 1K(or 300R)
1 x Sounder (10 mm pitch) max diameter of 12mm
1 x CR2032 vertical battery holder
1 x CR2032/LR2032 battery
1 x Push button 5mm pitch x 7.5mm pitch

Some Electronic expertise needed, and of course a good soldering teacher.

This project uses Lithium Button batteries, please note the warnings here – Do Not short out the batteries, and Do Not swallow them.

Morse Code

Morse Code decoding “tree”



If you wire two boards together (wire the two sounders together with a long bell-wire cable, be careful to get them both the same way around) you can make a telegraph system with a button and sounder at each end. Then you can practice sending and receiving for real….


Construction details are here