Adding Sidetone for Winkeyer Lite

I am the happy owner of a Winkeyer Lite. This electronic keyer is excellent for contest use, and many contest programs support it. The Winkeyer sends perfectly timed CW regardless how busy the PC's CPU. The picture below shows how the Winkeyer is connected.

How the Winkeyer is connected

When the Winkeyer is connected to the transceiver, you will hear the transceiver's sidetone. But sometimes the keyer is not connected, and the Winkeyer is now silent. I decided to add a sidetone, and make the circuit as simple as possible. The diagram is shown below:

A buzzer generates the sidetone.

Transistor Q2 is controlled by the Winkeyer's PTT line (default off). You have to activate PTT in the Winkeyer to make Q2 work. This can be done with the WKdemo test application.

The buzzer generates a 2,3 kHz tone (square wave). I can live with a high-pitched sidetone since the more pleasant sidetone of the transceiver is heard 99% of the time.

Winkeyer Lite with sidetone added.

73 from OZ1BXM Lars
Homepage: oz1bxm.dk