THE GREAT MULLARD MAGIC BLOG

When a valve is manufactured, it undergoes a process called evacuation where successive pumping operations remove air from the envelope prior to sealing.   However, even after evacuation, a small amount of gas remains - one part per one-hundred-thousand-million - as Cilla would have agreed, 'That's NORRA lorra, lorra gas!'    More gas may be released from the metallic components that comprise the electrode cage of a valve, gas that is trapped within the interstices of the metal structure especially if a valve is run under arduous operating conditions such that it gets extremely hot. Valve manufacturers include a component...

I did laugh when I saw the Cossor advert from the late 1920's and pictured below: - Just look at these fateful words, "......His clutching thieving fingers cannot harm this new Cossor...."    For those who are wondering why this bumbling prose has tickled my pique, its because I was once accused of having clutching thieving fingers!@#$%!  Alas my career in radio crime didn't take off and I did have ambitions of cat burgling an Enigma machine but I don't have a head for heights and besides, Enigma heists are passe as they have been done before.   Anyhow, enough...

 I had a very strange e-mail from a viewer in which he commented on my 'Mullard in the early 1950s' blog article, in particular my commentry about the Mullard LSD flash tubes.   He went on to lament that my article was just like most others on the 'net, a few words on these devices just copied from other websites!!!@*'? I must admit, I was flabbergasted, what nonsense, why would this person act like a radio part - hint - the bit that you turn to get more volume.  Anyhow, in order to satisfy any other affectionados of the Mullard...

Some of you may have seen the news report showing Her Maj boating on the Leeds & LIverpool Canal on the broad beam narrow boat, The Pride of Sefton in Burnley.    As she  cruised along, viewing  the old iron bedsteads, shopping trolleys and old tellies in the canal as she passed by, I wondered if these may have jogged her memory and did she then turn to Prince Philip and say, " I say, do you remember when we went to that valve making place nearby?"   Yes, they did visit the Blackburn site and details of this visit...

 It is said that a picture is worth a thousand words so for this blog entry, here we are - a picture which lists some of the valve failure modes discussed below as well as some extra ones:-