Welcome to the thermionic website

Devoted to electronic valves [also known as tubes], valve radio circuits and equipment

This picture shows an 813 based Hartley oscillator transmitter being tested with a makeshift power supply.

This transmitter was intended for the 160m (1.81-2.0 MHz) Amateur Radio band.

I dismantled it after a slightly disappointing period of testing and made another version using an 812A triode. This one works a whole lot better.

You can read more about this project and some others on my projects page.