Specialized - Cathode Ray ·CathodeRay
21EP4
Twenty-one-inch direct-view monochrome television picture tube with magnetic deflection and a P4 display screen. Manufacturer documentation places it in the high-voltage receiver CRT family, with construction optimized for bright rectangular picture presentation.
- Sections
- 1
- Base
- -
- Socket code
- B12A
- Base pins
- 5
- Nominal heater
- 6.3 V / 600 mA
Description
Direct-view cathode-ray picture tube for television display service. Electrical ratings, operating conditions, capacitances, optical data, and construction details were extracted from the supplied datasheet.
Socket description
Duodecal 12-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B12A
- Base pins
- 5
- Nominal heater voltage
- 6.3 V
- Nominal heater current
- 600 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
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
- 18000 V
Promoted ratings/characteristics read from the approved National Union datasheet.
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.