Roll your own valves (tubes)

A few weeks back – in the post about wartime crystal production – I made a tangential reference to my all time favourite YouTube video – Claude Paillard F2FO distilling down to less than 20 minutes his meticulous work making a triode valve, effectively by hand. Watching it again, this time I spent a bit more time looking over the many pages of background information he had posted on his website detailing his research into triodes of the 1920s, the techniques he used and the equipment he used or made to complete this project and create a very cute looking valve wearing blue shorts.

This prompted me to start a more methodical reading of the documents, and to work through the translations to ensure I understood what he had done. (Google translate is great, but it missed a significant amount.) If you’re vaguely interested in the technology of the earliest days of radio, and have ever wondered how these valves were made, the documents take you on a special journey through the eyes of an explorer with a brilliant workshop and skills to match. His research is comprehensive. By way of exploring how early valves were made he produces a full detailed and illustrated life story of the evolution of valve types and introduces important valve families like the 6L6 and its descendants like the 6V6 and the 807 of the late 1930s. He also takes you on an excursion to discover the history of creating an effective vacuum, critical in the creation of the valve aka the vacuum tube.

It’s also an enjoyable way to build up a French vocab for the terminology of valve radio gear. Along the way I stumbled across the Electropedia, a brilliant resource for translating technical terms from French to English with a number of other languages included. But some of the terms Claude Paillard uses reflect an earlier era and vocabulary. He talks about the plaque (plate) of a valve rather than l’anode. I’d love to find online versions of the French radio engineering references he cites from the 1920s.

Edouard Cliquet wrote a number of books explaining radio

Another plus of this experience is reading the history of radio from the perspective of a country other than Britain or the US. The French version of radio history introduces interesting characters and stories to the familiar names and places. An inspiration behind the work of F2FO is the history of the triode TM (Télégraphie Militaire). A good outline is at Michel Siméon’s website.

Paul Berché was another prolific author of French radio texts

Grinding quartz and holding a frequency during World War II

I’m a great fan of the Prelinger Archives which is home to so many items like this video I’ve heard about recently from various ham radio email lists.

I like how the components of the earliest electronics and wireless were so basic and ‘natural’. Think of hand made capacitors and resistors using traces of graphite on paper. Valves (or tubes) of course were another story but still capable of being ‘homemade‘.

I love the idea that an accurate, literally rock solid frequency could be achieved using a piece of a very common rock – admittedly a pure piece of quartz cut just so.

This video details the elaborate and meticulous manufacture of quartz crystals during World War 2 by Reeves Sound Laboratories in 1943.

The 41’24” video can also be viewed and downloaded via the Prelinger Archives.

Most of the ‘radio quality’ quartz was mined in Brazil which ceased its neutrality in 1942 and joined the Allies.

The story of quartz crystals during WWII is told in ‘Crystal Clear‘ by Richard J. Thompson Jr. (Wiley) 2011.


“In Crystal Clear, Richard Thompson relates the story of the quartz crystal in World War II, from its early days as a curiosity for amateur radio enthusiasts, to its use by the United States Armed Forces. It follows the intrepid group of scientists and engineers from the Office of the Chief Signal Officer of the U.S. Army as they raced to create an effective quartz crystal unit. They had to find a reliable supply of radio-quality quartz; devise methods to reach, mine, and transport the quartz; find a way to manufacture quartz crystal oscillators rapidly; and then solve the puzzling “ageing problem” that plagued the early units. Ultimately, the development of quartz oscillators became the second largest scientific undertaking in World War II after the Manhattan Project.” (from the book’s blurb)

Illustrating the precise angles needed for the AT and BT cuts of a quartz crystal…