Tubes? Who uses tubes anymore?

Published on 2010-02-28 by Mark VandeWettering

For the last week, I’ve been embarking on a ham radio “trip down memory lane”. Well, it would be memory lane if I had any real memories of the tube-based equipment that were staples of the ham shack until probably the 1970’s or so. But if I have a personal philosophy of my little projects, it’s that one has to look back to gain perspective about our current technology. Or something like that. Perhaps that’s just a rationalization for spending time reading old books about vacuum tube design. Or perhaps this is all motivated by the idea of building a radio that glows from scratch. Or, perhaps to demonstrate that I understand the similarities between tubes and FETs.

Whatever the motivation, I’ve been looking around at projects that people have done. A popular project seems to be “twinplex” radio, which uses a single dual triode tube in a regenerative receiver. Staring at circuits and reading Basic Theory and Application of Electron Tubes, I’m beginning to understand the functioning of these circuits. And, it turns out youtube has a lot of nice inspirational videos of people’s projects, such as the following:

Now that the winter is over, our local flea markets at Livermore and De Anza should be starting up again soon. Perhaps I’ll keep an eye out for the components.

Addendum: Here’s another link for inspiration.