THE GREAT MULLARD MAGIC BLOG

ADONIS & MARCONI OSRAM VALVES 1925

Posted by STEVE M on

ADONIS & MARCONI OSRAM VALVES 1925

Do you think this advert from 1925 is good? - I know my American friend Pamz will just LOVE THIS for Adonis is her nickname for ME! As we all know, Adonis is the perfect man, with a flawless physique, heart of gold and mind of steel, who makes hearts patter and gives girls butterflies in their stomachs with his presence. Hmmm, sounds like me but no references to toothpaste or dental floss!!!!!!!!!!! In Greek myth, Adonis was the son of Myrrha who was turned into a myrrh tree for incestuousness and gave birth to Adonis whilst in the form of a tree.  Adonis grew into an astonishingly handsome...

Read more →

MORE ON MULLARD DATE CODES - THE YELLOW PRINT VALVES

Posted by STEVE M on

MORE ON MULLARD DATE CODES - THE YELLOW PRINT VALVES

I am not going to get into the perennial discussion of the sonic properties of the yellow print valves over the stock boring white print ones but instead discuss A DIFFERENT advantage the yellow has over the prosaic white. Some of our eagle eyed readers will have noticed that the Yellow Print Old Shield Mullard valves have underneath the shield typically the valve notation in Mullard - Philips (ECC83) or even RETMA (12AX7) then underneath this is the elliptical BVA logo - just like for the white print valves....... But here's the rub - they yellow valves have a letter code...

Read more →

BRIMAR VALVE TYPE & DATE CODES - HOW TO INTERPRET THEM

Posted by STEVE M on

BRIMAR VALVE TYPE & DATE CODES - HOW TO INTERPRET THEM

Well, we did Mullard last week so this time, lets look at the Brimar type and date codes, oft seen on valve envelopes in minuscule inked print, but what do they mean? Brimar codes come in two parts separated by a forward slash "/". The first part, of format number-letter-number is the date code where the first number signifies production week of month, the following letter signifies the production month and the second number signifies the production year. First number: - 1 = week 1 of production month 2 = week 2 of production month 3 = week 3 of production month 4 = week 4 of production...

Read more →

MULLARD LONG LIFE TINTED TELEVISION PICTURE TUBES

Posted by STEVE MYCIUNKA on

MULLARD LONG LIFE TINTED TELEVISION PICTURE TUBES

Today's evocative photo shows Mulard Long Life picture tubes undergoing life tests at the Mitcham plant sometime in mid 1952.     On the test rig, applied voltages were regulated and the beam current was fixed.  The test card used closely simulated a screen raster.  Here we see Trevor Wibbley about to take voltage characteristc measurements, light output measurements and assess subjective picture quality. What is special about the tubes pictured is that they were the first of those produced by Mullard with tinted glass faces.   The tinting was introduced as an attempt to boost contrast when viewing in...

Read more →

MULLARD VALVE ETCHED CODES - HOW TO INTERPRET THEM

Posted by STEVE M on

MULLARD VALVE ETCHED CODES - HOW TO INTERPRET THEM

There is much conflicting fokelore on the internet about the Mullard etched valve codes so I thought I would add our two penny-worth. The etched codes have value to us today as they contain two discrete nuggets of information; firstly, should a valve loose it's printing you can identify the valve type and secondly, you can glean the production site and the month and year of manufacture. The etched codes, in general, comprise of two lines stacked vertically with the top line being a three character Engineering Code with the third digit signifying the development iteration of the valve.  For example,...

Read more →