Andy Cowley's Valve Pages


Valve History Articles

Old British Valve Data

Valve Links

Photo Galleries

Old Valves
British Valves
Hivac Box
Valve Boxes


The pre-war British valves gallery pictures nearly sixty valves from the era before U.S. and European valves became more or less standardised and equivalent. Many have links to PDF data sheets. A few foreign valves, as would have been used in the U.K., are included.

The valve boxes gallery presents pictures of over 130 different boxes from all periods of valve manufacture from the early 1920s to the present day.

The power valves section reflects my interest in Amateur Radio and has examples of many of the classic transmitter valves used by amateurs from the 1940s to the present day. Most of the classic audio output valves used in hi-fi and music amplifiers are also represented.

A fairly large selection (>20) of rectifiers, mostly suitable for consumer items are pictured in the rectifiers gallery.

The gallery of optoelectronics contains all the vacuum and gas-filled valves used for display or light detection. Included are tuning indicators, photocells, flash tubes, a vidicon and a photomultiplier.

Everything else is lumped together in the 'other unusual things' gallery. There are acorns, nuvistors, electrometer tubes, barreters, time delay relays and laboratory and test samples.

The "Shire Three " vintage radio documents the project by a group of us at the world iconShirehampton Amateur Radio Club to build a 1920s radio using authentic parts.

A vintage portable radio.

Articles on, and items from, Valve History

Fleming's patents for the very first electronic valve.

A lecture on Fleming given by Prof. G.W.O. Howe on the fiftieth anniversary of Fleming's invention of the first electronic valve. Brutally honest reflections by someone who knew Fleming, De Forrest and Marconi personally.

A timeline of the development of valves and broadcasting in the U.K..

A history of Mullard with some pointers on dating the PM series valves.

A history of A.C. Cossor, who claimed to be the 'world's first valve manufacturer'.

Some 1950s adverts for classic audio valves.

A project to recreate a 1920s radio at world iconShirehampton ARC

Data Sheets, Equivalents and Short Data for British pre-WWII valves

Equivalents and Substitutes

All data is taken directly from manufacturers published data sheets. Some compilations have been found to be unreliable, particularly about equivalences. The manufacturer is important as well as the valve type, since valves with the same type number from different manufacturers may vary significantly. I have made a full table of manufacturer recommended substitutions with links to PDF data sheets, where available. These should be fairly reliable (e&oe). All data is from the 1930s.

Mullard Data Books

These books all contain full page sheets on each valve covered with at least one curve for each valve. The complete index has an ordered table of all the valves covered in these books with links to their data sheets as full page PDF files. Each book also has short data on some obsolescent types, circuits, articles on construction and lists of valve sets for commercial radios and kits. The Mullard Rapid Valve Guide and the 1933-4 Mullard Master Valve Guide were kindly loaned by Dave, G3YNH. The 1937-8 Catalogue of Mullard Master Valves is unfortunately missing page 111.

Cossor Data Book

This Cossor manual has interesting articles on: valve fundamentals; valve construction and valve types as well as full page descriptions with curves of sixty valve types. There are also tables of equivalents, re-valving sets for radios and suggested circuits. Every page is available as a PDF file.

Leaflets with short data and advertisements