THE GREAT MULLARD MAGIC BLOG — RETMA

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: -   ...