THE GREAT MULLARD MAGIC BLOG

I have just received an e-mail asking for details of military valve markings so here's a little primer for anyone who might have a similar interest. Valves used by the British military Armed Services were marked with a  CV or common valve name which was defined by the  Inter-Service Technical Valve Committee in 1941.     Often, below the CV number,  a two part  alpha code of the form KB/xx  or JB/xx will be seen  which gives the devices manufacturing specification and qualification .  For the first part of the alpha code, the K designates a valve manufactured to specification K1001 or K1006; similarly a J designates a...

I did titter when I saw the above illustration from a 1950s comic book, what a treat to see the Man With an Electronic Brain and let me tell you, I have met and known a few numpties who would benefit from some electronic augmentation too. But wait a minute, like me, are you thinking that the electronic brain looks rather similar?  Could it be... yes, I think it is, what do you think........? Well beat me on the bottom with a copy of Radio Bygones magazine, that electronic brain bears more than a passing resemblance to the Defiant M900...

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...

Well, the war was over and 1946 dawned. America had cut off Lend-Lease money to the UK and materials for home and export production were in short supply. There existed a massive surfeit of military surplus electronics which was growing at an alarming rate as war supplies were withdrawn from various theatres of operation. At this time, the great military surplus gravy train was about to commence where not only radio equipment and componentry were available for knockdown prices but military vehicles and even aircraft – and ex RAF pilots to fly them – typically those that did not possess...

It was a difficult time at Mullard during wartime. First of all, they were cut off from Philips - in more ways than one as the Philips and Mullard parts of the Blackburn facility were segregated with building doorways staffed by Corps of Commissionaire guards who were instructed to not let any Philips personnel into the Mullard areas. The problem was that Philips senior staff were now treated as suspect due to having family members in enemy occupied territory and were hence a coercion and security risk.  As if that wasn't enough, the jolly Germans had a crack at the...