THE GREAT MULLARD MAGIC BLOG

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...

Today, I had a lovely e-mail from Christo in South Africa who needed some help in getting his prized radiogram working.   Unfortunately, I was unable to help but was able to comment "WHAT A RADIOGRAM!"  and I think, as this blog entry progresses, you will see why! The radiogram appears to be a SA home market only item, made by Mullard and termed the Voortrekker, only 54 of these leviathans were ever built and the famous Afrikaans short story writer Jan Sebastian Rabie (14 November 1920 - 15 November 2001) had one.  Anyhow, enough waffle, here's the beast:- Christo is trying to restore the...

We hear so much about Donald Trump but how many of you realised that he liked early Philips sets - not many I'll bet.   Could this be true or another piece of fake news.   You need irrefutable evidence to make such claims surely, and here it is, look closely at the following photograph:-   As you can see quite clearly, we have a young Donald Trump, in his underpants standing atop a Philips 2531.  The Philips 2531 was quite a technological marvel at introduction in 1930, lasting for a production run of two years in which 42000 units were...

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...