THE GREAT MULLARD MAGIC BLOG

OK, previous blog entries have described the “3 Services” legacy valve numbering systems as well as the GPO numbering system and as we have seen there was little if no commonality. Something had to be done and in 1941 everyone agreed to use a common system of nomenclature known as the COMMON VALVE or CV numbering. The agreement was a bit of a compromise as it only applied to NEW valves so there would always be old system labelled valves kicking about in stores.  However, a volte-face occurred in 1943 as the Navy kicked up a fuss, so all valve...

Hi peeps, well, in response to another valve related query, this time about 'JAN codes', I thought I would pen a little information nuggett here today. I shall be doing a further more detailed blog entry on military coding history and types soon but for now here's a quick info - bite. The JAN code is of course the US Military Joint Army Navy coding introduced in 1942 in which the code for a particular valve type comprises of an alphanumeric code, for example VT-114 and additionally a three digit alpha code. I will deal with the former in more...

Having now done the WW2 Allies valve numbering, it would be churlish to not include the other sides' rohren numbering system now wouldn't it?   Now let's see what's left still to do, oh yes, the CV system, the Cyrillic system and the GPO numbering system, phew, better get blogging and then we can get back to the story of Mullard - what would you all like next -  ground breaking  products in the 1950's, semiconductor manufacture in the 1950's or expansions and endowments (yes there's more!) in the 1960s - you choose - let me know using the comments function?    KRIEGSMARINE &...

The US Signal Corps, used a numbering system of VT numbers, incidentally, the VT stands for Valve, thermionic – three electrode – a bit of a to do if you want to list a beam tetrode!!!! .  The military look up table MIL-HDBK-213A is required to decode the 289 valves identified in this manner.  However, for the ardent audiophiles, I have prepared this list of the most desired devices:- VT4C = 211 VT66 = 6F6 VT74 = 5Z4 VT80 = 80 VT94 = 6J5 VT95 = 2A3 VT100A = 807 VT107 = 6V6 VT115 = 6L6 VT126 = 6X5 VT144 =...

  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...