A Journey into Building Radio Transmitters with Vacuum Tubes

A copy from an old italian magazine of amatorial electronics, proposing an add-on for tube receivers. The add-on was a simple one-tube short-wave transmitter leveraging the same power supply already available in the receiver. This circuit fascinated me when I was just a teenager. I was quite a nerd when I was a teenager. Sure, besides being very c
A Journey into Building Radio Transmitters with Vacuum Tubes - schematic

lever at school, I was into any sort of strange hobbies including electronics. My father was seemingly proud of this. Perhaps my mother was a bit concerned, instead. You know, a male teenager is rather expected to hang out with friends, seek a girlfriend, etc. The project reported in that old magazine fascinated me at that time, because I had a tube receiver at home, and I got a spare tube from another old receiver so I apparently had almost all the ingredients. The only missing piece was the plate RF choke, but I managed to build what at that time I presumed to be a good approximation of it. So I tried! But I was unsuccessful. The reason of that early insuccess was a fundamental lack of specific knowledge in RF electronics. I had no actual chance to spread RF in the air, despite the schematics and the components, because for instance I knew nothing about antennas, transmission lines, and impedance matching. I will always be grateful to the poor victim of these early and cruel experiments, namely, a 6V6 tube that has survived nevertheless. Vacuum tubes are generous and patient, they tolerate our mistakes, and this is the main reason why I keep loving them for my RF experiments, despite the dangerously high voltages required for operation. First serious attempt: one-tube tx using a Sovtek 6L6 WXT+ tetrode in a Hartley electron-coupled oscillator. Circuit schematics is missing, but it was very similar to the one I attempted...

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