Specialized - Cathode Ray ·CathodeRay
3FP7
RMA 3FP7 electrostatic-focus and electrostatic-deflection oscilloscope CRT with P7 phosphor, supplementary high-voltage anode and 6.3 V 0.6 A heater.
- Sections
- 1
- Base
- 4B
- Socket code
- -
- Base pins
- 12
- Nominal heater
- 6.3 V / 600 mA
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- 4B
- Socket code
- -
- Base pins
- 12
- Nominal heater voltage
- 6.3 V
- Nominal heater current
- 600 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
4B - Terminal pinout
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
Section ratings
1 physical section, each with unique specifications.
Section 1
Cathode Ray
- Max plate voltage
- 4400 V
RMA 3FP7 electrostatic-focus/deflection CRT, P7 phosphor. Max supplementary anode3 voltage 4400 V (promoted high-voltage maximum), anode2 max 2200 V, anode1 focus max 1100 V; grid never positive, anode2-to-deflection electrode peak max 550 V, heater-negative-to-cathode DC max 125 V, grid resistance max 1.5 MΩ, deflection-electrode circuit impedance max 1 MΩ. Typical (Va3/Va2/Va1) 2000/2000/575 V, 3000/1500/430 V, 4000/2000/575 V; cutoff -60/-45/-50 V; DJ1/2 sensitivities 0.115/0.115/0.086 mm/V, DJ3/4 0.155/0.156/0.117 mm/V. Capacitances grid-all 3 pF, cathode-all 7 pF, DJ1-DJ2 2 pF, DJ3-DJ4 2 pF, DJ1-all ~9 pF (source scan ambiguous), DJ3-all 7 pF, DJ1 excluding DJ2 7 pF, DJ2 excluding DJ1 7 pF, DJ3 excluding DJ4 5 pF, DJ4 excluding DJ3 6 pF. Side snap cap for anode3. Recommend Va3 >=3000 V for high-velocity scanning.
Source-dependent data
Operating conditions by source
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.