Virtual Valve Museum

Virtual Valve Museum

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This CRT measures 160x40mm overall and has a 9-pin B9 base.

This CRT carries the marking Osram 43 in red on the glass.

Heater voltage 4V
Heater current 1.1A
Max anode 3 voltage 800V
X-plate sensitivity 100/Va3 mm/V
Y-plate sensitivity 90/Va3 mm/V
Screen YY2 (yellow, ultra short persistence)
Desirable spot size * 1mm
Typical operating conditions
Anode 1 and 3 voltage 800V
Anode 2 voltage 135V
Beam current 3.0µA

*: Focus quality: with Va3=800 and Va2 and Vg adjusted to give an optimum-focus raster of convenient size and of light output 0.002 candles, the +ve grid drive from Vg (blackout) is noted (= x). Then, with the beam just "blacked-out", a nominally square wave +ve pulse of peak value x volts and of width 100µs at 100cps applied between cathode and grid, and with the high frequency timebase set to produce a line of 2.5cm in the x and y axes successively (with no adjustment of focus between measurements in the two axes), the line width as measured at the centre of the trace must not exceed 1.0mm.

Pin Function
1 X1
2 Y1
3 Anode 2
4 Heater / cathode
5 Heater
6 Modulator
7 Anodes 1 and 3
8 Y2
9 X2

Quarter view