THE GREAT MULLARD MAGIC BLOG

The unreliable 'split-pin' PM series were swiftly replaced by valves having a new improved base. The base was characterized by having the same ebonite base but the inset pins were now tubular, having two slots in orthogonal configuration with electrode lead arrangements..outs being passed up the pin centre and connected by soldering at the tips. The bases now had a paint filled groove also labeled ‘A’ to denote the anode connection adjacent to the anode pin – This paint was applied by deft fingered young ladies but the process was deemed too labour intensive and so was discontinued in 1928,...

Well, using the recently developed Philips Azide technology for coating and preparing cathodes with barium oxide, the age of the dull emitter had dawned. Following technology transfer from Eindhoven to the Balham works, the production of the PM series valves commenced ( – PM for Philips – Mullard – geddit????.......) with the PM 3 and PM4 in 1925.     Original valve box images  by kind courtesy of Alan Wyatt of The National Valve Museum = see more at www.r-type.org  These early PM valves were very distinctive in having four brass pins, each with a single slot cut into them, set...

 Well, we are not going to discuss ‘Yus my dear’ Arthur Mullard but the dashing, First World War Captain Stanley R. Mullard who worked on the production of bright emitter thermionic valves for the Admiralty and a clever chap he was too holding six patents jointly with the Admiralty. Shortly after the end of the war during 1919, he left the Admiralty joining the Z Electric Lamp Co as their managing director. By mutual arrangement, valves were manufactured using Stanley’s patented technology and sold principally to the Admiralty and Post Office under the S.R. Mullard brand.When the Z Electric Lamp...

We tend to think of 'radio and technology bloopers' as a fairly recent trend on TV, witness the DAC90A in recent episodes of Foyle's War and the time machine advert run by Hovis a couple of years ago, however, similar things also happened some 40 odd years ago as I recall one chortle-worthy instance in an Avengers episode where a chap made up to look like a Chinese mandarin was busy playing a chess game by radio and transmitting his next fiendish move using a BC221 wavemeter, not that it bothered Tara King though....... Sticking with The Avengers theme,  I thought you may...

Well, an iconic airborne station forms the subject of today's blog.  Here we have a still, captured form the 1951 film, The Clouded Yellow, featuring Trevor Howard & Mrs. Granger, sorry, Jean Simmons.   As fugitives from justice hurrying though the Lake District, the police brought in a radio lorry, fitted out with an R1155/T1154 station, courtesy of RAF Mountain Rescue to co-ordinate capture.  In our first picture you can see Kenneth More ( Douglas Bader himself!) as the arresting Detective.  The Clouded Yellow was based on an original script by Janet Green. It was developed by Sydney Box but he had...