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7BP7A

Seven-inch direct-view radar CRT with magnetic focusing and deflection, designed as a replacement for the 7BP7. Its P7-type long-persistence screen supports persistent radar indication.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: -
Socket code: DUODECAL11
Base pins: 8
Nominal heater: 6.3 V / 0 mA

Description

Seven-inch direct-view radar CRT with magnetic focus and magnetic deflection; replacement for 7BP7 with long-persistence P7-type display.

Socket description

Duodecal 11-contact CRT base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: DUODECAL11
Base pins: 8
Nominal heater voltage: 6.3 V
Nominal heater current: 0 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

X-ray radiationInterelectrode capacitances

Max plate voltage: 8000 V

CRT maximum accelerating/anode/ultor voltage is promoted to MaxPlateVoltage; additional electrode ratings, capacitances, operating conditions, deflection/focus and optical data are preserved as parameters.

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.

Data set 01

1971 RCA HB3 Binder 1 of 7

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

Peak heater-cathode voltage
125 V
HeaterNegative
Peak heater-cathode voltage
125 V
HeaterPositive
Typical anode voltage low
4000 V
TypicalOperationLow
Typical anode voltage high
7000 V
TypicalOperationHigh
Maximum accelerating/anode voltage
8000 V
ANODE VOLTAGE
8000 V
Maximum
GRID-No.2 VOLTAGE
700 V
Maximum
PEAK GRID-No.1 DRIVE FROM CUTOFF
65 V
Maximum
Anode Voltage' 4000
7000 V
Grid-No.2 Voltage 250
250 V
Grid-No.l Voltage Range° -25 to -70
-25 to -70 V
Focusing-Coil Current• 75 to 102
99 to 135 mA
Grid-No.l-Circuit Resistance
1.5 MΩ
Maximum

Capacitance

Grid 1 to all other electrodes capacitance
8.5 pF
Approximate
Grid 2 to all other electrodes capacitance
7 pF
Approximate
Cathode to all other electrodes capacitance
5 pF
Approximate

Characteristic

Deflection angle
53 degrees
Approximate
Deflection angle
53 degrees
Approximate