THE GREAT MULLARD MAGIC BLOG — mullard crt

In the very early days of television, the bulbs for cathode ray tubes (CRT) were blown by hand, however, due to volume requirements, most CRT bulbs were moulded, being made in two parts with the flattened end termed the face-plateand the pear shaped body termed the cone.  As the separate parts were delivered to the Mullard factory, at this stage in the early 1950s that means the Blackburn works, the first stage after inspection for blemishes was to join the parts.  Any components marred by blemishing were returned to the glass moulders for re-melting - waste not want not! Joining was carried...

Well, a CRT is a thermionic electron tube so I thought we would follow our popular blog series on how valves were made with a similar one detailing the manufacturing process for CRT employed by Mullard. Let's start with the basics, we can list the CRT main component parts as the envelope, the electron gun and the screen. The envelope, consists of a funnel shaped glass bulb which was either round or rectangular in section and closed at it's widest end with a flat glass faceplate and terminated at the other end by a narrow tubular neck. The electron gun, produced a narrow beam of high...

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...