THE GREAT MULLARD MAGIC BLOG RSS



THE GENERAL POST OFFICE (GPO) VT VALVE NUMBERING SYSTEM

Confusing or what, the GPO had their own Valve - Thermionic numbering system comprising of a sequence of numbers in range from VT17 to VT207.  Although this alphanumeric code followed the same form as the US Signal Corps one it was quite different.    I have produced a look up table that related GPO VT number with UK CV number and commercial equivalent numbers - a first for the internet I think.  Enjoy:- GPO VT NUMBER CV NUMBER COMMERCIAL NUMBER   VT19 CV1612 VT9B VT24 CV1636 LS5 VT25 CV1637 LS5 VT26 CV1600 CAT1 VT27 CV1601 CAR1 VT31 CV1638 4101D VT33 CV1642 DER VT34 CV1614 ES1500A VT35 CV1615 ESU1500 VT36 CV1602 CAR4 VT38 CV1645 E133 VT40 CV1647 LS5B VT46 CV1616 4104A VT47 CV1603 4104B VT50...

Continue reading



WW2 GERMAN EIGANTUM VALVE CODES

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 & WERMACHT These German Eigantum valves carry an alphanumeric code in the sequence: two letters, two numbers, one letter, two numbers....

Continue reading



THE PRE COMMON VALVE NUMBERING SYSTEM USED BY THE BRITISH ARMED FORCES

Having broken off from my historical diatribe on Mullard, here are a few useful snippets about the pre CV valve numbering system used by the British Armed Forces - here is an explanation of what the various alpha suffix codings used by the different service arms mean - now you'll at least be able to identify the valve type if not the type number:- British Army Comprises of an alpha coding which signifies the valve use or configuration followed by a numeric code that signifies valve.  The most commonly seen are listed below:- ACR - Army  cathode ray tubeAR - Army receiving valve ARD - Army receiving diodeARDD - Army receiving double diodeARH - Army receiving hexodeARP - Army receiving pentodeARS -...

Continue reading



THE WW2 US ARMY SIGNAL CORPS VALVE NUMBERING SYSTEM -

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 = 813 VT145 = 5Z3 VT217 = 811 VT229 = 6SL7GT VT231 = 6SN7GT VT197A = 5Y3GT VT206A = 5V4G VT244...

Continue reading



THE JAN CODE - WHAT DO THE ALPHANUMERIC AND ALPHA CODES MEAN?

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 detail later, but the alpha code is a manufacturer code. Here is a short listing of the most commonly seen...

Continue reading