THE MULLARD CATHODE RAY TUBE TYPE NUMBERING SYSTEM

Today, we are going to look at the Mullard CRT numbering system which gave type numbers as two letters followed by two groups of numbers which translated as below: - 

the first letter

D - electrostatic focussing  and deflection CRT as used in oscilloscopes.

M -  magnetic focussing and deflection CRT  as used in TV and radar.

the second letter

B - screen phosphor gives a blue short persistence trace.

F - screen phosphor gives an orange long persistence trace.

G - screen phosphor gives a green medium persistence trace.

P - screen phosphor is double layer combining a blue short persistence trace with a yellow long persistence afterglow.

R - screen phosphor is single layer giving a long persistance green trace.

W - screen phosphor gives a medium persistence white luminance for television picture tubes. 

first figure group

4 - screen diagonal or diameter of 4 cm or 1.75 ins.

6 - screen diagonal or diameter of 6 cm or 2.5 ins.

31 - screen diameter of 31 cm or 12 ins.

36 - screen diameter of 36 cm or 14 ins.

41 - screen diameter of 43 cm or 17 ins.

second figure group

This figure grouping which is generally separated from the first grouping by a hyphen is a design development reference, for example the MW36-22 and MW36-24 are both direct viewing television picture tubes designed for magnetic deflection and focussing with a 36 cm or 14 ins screen - the only difference is the 22 suffix was superceded by the 24 suffix unit.