THE GREAT MULLARD MAGIC BLOG — VALVE NUMBERING SYSTEM

Yo peeps, today we are going to look at the RETMA valve numbering system. The Radio Electronics & Television Manufacturer's Association was formed in early 1953 and were pivotal in ensuring standardisation of American Valve numbering using the RETMA system.  Although primarily an American system, it was also used extensively in Europe with Mullard using it to label American valve types imported or manufactured at the old Edswan works.  In Britain, Brimar used the system extensively for most of their valve products.  A RETMA valve code always takes the following form: -  NUMBER PREFIX/LETTER GROUP/NUMBER SUFFIX/ADDITIONAL LETTER(S) where: -   ...

Well, Mazda were another manufacturer who wanted to stand out and indeed made their own version of the Octal base with a fatter spigot known as the Mazda Octal or MO base.    Their valve numbering system was a bit kooky too and needs some explanation.  The typical Mazda valve type number was an alphanumeric affair comprising of; a numerical prefix followed by a letter which in turn was followed by a mumerical suffix. The numerical prefix always indicated the heater voltage EXCEPT where 10, 20 & 30 were used which indicated the heater current draw in 0.1A.  A further...

Those clever chaps at GEC-Osram made some of the most memorable and sought after valves made by any manufacturer, they chose valve base styles that were not used by anyone else at the time and envelope shapes which were not at the time used by anyone else so why should their valve numbering system be the same as anyone elses?     Anyhow, I digress for here is a handy little table that will allow you to classify the kinky GEC from the vari-mu GEC - I hope you will find it useful: - Letter Identifier Classification A Industrial device...