Oscillators part 3a - Vacuum Tubes -  

In Russian they are just called lamps (which would be the typical word for a light bulb). When I lived in Odessa ~15y ago, you could still pick them up at the electronics market. Presumably new old stock or recycled. Unfortunately I never got into them at the time.

Yeah, World Radio History is an absolute goldmine of out of date publications... I often use it to browse all the old UK electronics magazines that I so loved growing up in the 1970s and 1980s and the Bernard Bambani books that were such an invaluable resource in roughly the same time scale. Can't rate that site high enough!

Excellent lesson Bill.

Very interesting

Very Interesting. Thanks Bill. Another type of oscillator which fascinates me is the Neon Lamp Oscillator. You can build relaxation oscillators, flip-flops and all sorts of interesting variations with just some neon lamps, resistors and capacitors. They run on 90v at very low currents.

V1 is an ECC85 AKA 6AQ8, V2 is a triode heptode ECH81 AKA 6AJ8