THE GREAT MULLARD MAGIC BLOG — crt testing

 After exhausting and capping, the tubes were fitted with their bases and still in their linen bags, were transferred onto a conveyor belt where each tube was plugged into an adaptor which supplied the appropriate voltages to the heater, cathode, grid and first anode as well as a heat from an embedded element which baked the cement inside the base cap thus hardening and attaching the base to the bulb neck: - After heating and as power was applied to the tube, the heater fired and cathode emission commenced and this initial 'firing' reduced a part of the cathode...

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...