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NC13 'compass' CRT

Size The CRT measures 495x178mm overall and has a 12 contact base.

This CRT is described as a compass tube. It was supplied with markings fixed to the face, one section of which can be seen on the picture further down this page. It has a green medium persistance screen.

Heater voltage 4V
Heater current 715mA
Max anode 1 voltage 500V
Max anode 2 voltage 1kV
Max anode 3 voltage 4kV
X-plate sensitivity 520mm/V/Va3
Y-plate sensitivity 520mm/V/Va3
Typical operating conditions
Anode 1 voltage 450V
Anode 2 voltage (focussing) 380 to 500V
Anode 3 voltage 2.2kV
Vmod for beam cut-off 30 to 90V
Xs - Xp 4.5pF
Xs - rest 14.6pF
Xp - rest 14.0pF
Xf - Ya 4.4pF
Xf - rest 14.9pF
Ya - rest 13.8pF
(Xs+Xp) - (Ya+Yf) 2.7pF
Mod - rest 8.6pF


Pin Function
1 Modulator
2 Cathode
3 Heater
4 Heater
5 Anode 1
6 Anode 2
7 Blank
8 Y-aft
9 Y-fore
10 Anode 3
11 X-starboard
12 X-port

Quarter viewThe original markings, one section of which remains, were arranged in 10's from 0 to 180 each side. Four letters would have been marked as well, F, A, P and S for Fore and Aft, Port and Starboard. The NC marking indicates this to be a Navy CRT. The figures were red on the port side and green to starboard.



View of the electron gun.

This file was last modified 14:50:03, Tuesday September 02, 2014