30C12

      The 30C12 is a cathode ray tube which is a precision constructed instrument.It provides bearings with an error not exceeding ±1 at any point.No degree scale is attached but a centre cross and mark are provided,in line with the axis of the Y Plates,accurate to ±25°.The 30C12 is suitable for use in "Pulse D.F."systems and may be supplied with any of the standard phosphor screens.
      The heater voltage which is short of Vh is 4.0 V.The heater current which is short of Ih is 0.72 amps.The maximun 1st amode voltage which is short of Va1(max) is 500 V.The maximun 2nd amode voltage which is short of Va2(max) is 1000 V.The maximun 3rd amode voltage which is short of Va3(max) is 4000 V.The average sensitivity of X plates is 520 mm/V.The average sensitivity of Y plates is 520 mm/V.
      The dimensions of 30C12 is as follows. The maximum overall length is 498 mm.The maximum bulb diameter is 175 mm.The maximum neck siameter is 65 mm.The approximate nett weight is 2.25 lbs.The approximate packed weight is 16.25 lbs.
      The typical operation of 30C12 is as follows.The 3rd anode voltage is 2200 V.The 2ND anode voltage is 440 V.Note:2rd anode voltage for focus decreases with increase of beam current and the above figure is the voltage required at low currents.The 1st anode voltage is 450 V.Negetive bias on control grid for cut-off beam current is from 30-90 V.