Morse code – test oscillator – construction

Construction requires some soldering knowledge not covered here, If you are not competent at soldering seek some assistance from your local hack-space, school, electronics or amateur radio club. There is a very comprehensive guide to simple soldering by @eevblog here

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

The circuit diagram, component list and PCB ordering details and morse code information is here

20160514_180253 The empty Morse test PCB (printed circuit board) component side up (this is the side you put the components on to).
20160514_180324 First find the 1K resistor (coded brown,black,red) push the leads through the two holes on the PCB
20160514_180356 Next push the legs of the button into their respective holes, It may take a little gentle wiggling to get it to fit flat on to the PCB
20160514_180410 20160514_180627

Fit the LED next, be careful to get it the right way around, The long leg need to go into the hole with the little + sign near it.

Solder these components ensuring that you haven’t bridged the connections. and cut off the leads just after the solder joint.

20160514_180724 Insert the sounder, note the plus symbol on the sticker this indicates the positive(+) lead. This lead needs to go towards the hole on the PCB with the + near it.

Solder the leads behind, and again cut off the leads flush to the solder joint.


Push in the battery holder, All three legs must go completely through the board so the bottom of the holder is flat to the PCB.

Solder it in place


The underside of the PCB should look like this (or better) Make sure all legs have solder on them, that there are no long leads left and there is no solder blobs connecting any two pins. (especially check the led connections as these are the two closest together.)


Offer up the battery to the battery holder, ensuring you have matched the + on the battery with the + on the holder.

When you are are you have it the right way around, push it fully into the holder.