This circuit was found in a 1942 publication. It uses 4 tubes, as the rectifier is not represented as such. The circuit does not use a transformer in the power supply and has a counterphase output. The phase shift is done by transformer.

This circuit was found in a 1942 publication. It uses 4 tubes, as the rectifier is not represented as such. The circuit does not use a transformer in the power supply and has a counterphase output. The phase shift is done by transformer.