THE GREAT MULLARD MAGIC BLOG — brimar

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: -   ...

Mama Mia!  An e-mail from Vigata in Sicily enquiring about when certain valve bases were introduced.   I know a valve dealer from Sicily you know, he's from Messina and ever such a nice chap but I digress........ There exists a whole raft of valve bases, however, I shall deal with only the most commonly seen bases and their dates of introduction in the following table:- Year of Introduction Valve Base Type Descriptive notes 1916 B4 Introduced by French valve manufacturer Duclos-Fivre 1927 B4 + side screw Introduced for indirectly heated cathodes 1928 B4 + top cap VHF/ UHF anode top...