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Power - TV Horizontal Output (sweep) ·BeamPower

17GJ5A

Beam-power tube designed for high-efficiency television horizontal-deflection amplification, with controlled heater warm-up and high pulse-voltage capability.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 9QK
Socket code: B9E
Base pins: 9
Nominal heater: 16.8 V / 450 mA

Description

17GJ5A Beam Power Tube

A Novar-type beam power pentode designed for high-efficiency horizontal-deflection-amplifier service in television receivers.

Overview

The 17GJ5A is a beam power tube of the Novar design, primarily intended for use in the horizontal-deflection-amplifier circuits of television receivers operating on 525-line, 30-frame systems. It is electrically identical to the 6GJ5A and 12GJ5A except for its heater ratings. It is also closely related to the 17GJ5, sharing identical electrical characteristics but differing in physical construction; the 17GJ5A features a shorter bulb and a base equipped with an exhaust tip at the bottom.

Physical Characteristics and Base

The 17GJ5A is constructed with a T-12 glass envelope and a Novar Button 9-Pin base (E9-88), which requires a standard Novar 9-contact socket. The physical dimensions of the tube are as follows:

Maximum Overall Height: 3.505 inches
Maximum Seated Height: 3.125 inches
Maximum Diameter: 1.562 inches

Depending on the specific manufacturing variant, the tube may incorporate a top cap (types C1-2, C1-3, or C1-33) to facilitate the plate connection.

Heater Ratings and Pinout Configurations

Heater Specifications

The 17GJ5A features an indirectly heated cathode with the following heater ratings:

Heater Voltage (AC or DC): 16.8 V
Heater Current: 0.45 A (with a tolerance of 0.450 ± 0.030 A)
Average Warm-up Time: 11 seconds
Peak Heater-Cathode Voltage: ±200 V max
Average Heater-Cathode Voltage: 100 V max

Pinout Configurations

The physical connections of the 17GJ5A are documented in two distinct configurations depending on the envelope and top-cap arrangement:

Configuration A (9QK Pinout)

This configuration does not utilize a top cap, routing all active electrodes through the base pins:

Pin 1: Grid No. 1 (G1)
Pin 2: Grid No. 2 (G2)
Pin 3: Cathode / Grid No. 3 (K, G3)
Pin 4: Heater (H)
Pin 5: Heater (H)
Pin 6: Plate (P)
Pin 7: Grid No. 2 (G2)
Pin 8: Internal Connection (IC) — do not use
Pin 9: Internal Connection (IC) — do not use

Configuration B (Top-Cap Plate Pinout)

This configuration utilizes a top cap for the plate connection, altering the pin assignments on the base:

Pin 1: Grid No. 1 (G1)
Pin 2: Grid No. 2 (G2)
Pin 3: Cathode (K)
Pin 4: Heater (H)
Pin 5: Heater (H)
Pin 6: Grid No. 1 (G1)
Pin 7: Grid No. 2 (G2)
Pin 8: No Connection (NC)
Pin 9: Internal Connection (IC)
Top Cap: Plate (P)

Electrical Characteristics and Class A1 Operation

Direct Interelectrode Capacitances

The approximate direct interelectrode capacitances of the 17GJ5A are:

Grid No. 1 to Plate: 0.26 pF
Grid No. 1 to Cathode, Heater, Grid No. 2, and Grid No. 3: 15 pF
Plate to Cathode, Heater, Grid No. 2, and Grid No. 3: 6.5 pF

Typical Operating Points

The tube can be operated under Class A1 conditions in either a triode-connected or pentode-connected configuration. Typical operating parameters are outlined below:

Parameter	Triode Connection	Pentode Connection (Low Voltage)	Pentode Connection (Normal)
Plate Voltage	150 V	60 V	250 V
Grid-No. 2 Voltage	150 V	150 V	150 V
Grid-No. 1 Voltage	-22.5 V	0 V	-22.5 V
Plate Resistance (Approx.)	—	—	15,000 Ω
Transconductance	—	—	7,100 µmhos
Plate Current	—	390 mA*	70 mA
Grid-No. 2 Current	—	32 mA*	2.1 mA
Mu-Factor (G2 to G1)	4.4	—	—
Grid-No. 1 Voltage for Ib = 1 mA	—	—	-42 V

Note: The low-voltage pentode characteristics are measured using a recurrent waveform method to prevent exceeding the maximum ratings of the tube during testing.

Horizontal-Deflection Amplifier Service

When operated in a 525-line, 30-frame television receiver system, the 17GJ5A must be operated within its Design-Maximum Ratings to ensure reliability and longevity.

Design-Maximum Ratings

DC Plate Supply Voltage: 770 V
Peak Positive-Pulse Plate Voltage: 6,500 V (The pulse duration must not exceed 15% of a horizontal scanning cycle, or 10 µs)
Peak Negative-Pulse Plate Voltage: 1,500 V
DC Grid-No. 2 Voltage: 220 V
DC Grid-No. 1 Voltage: -55 V
Peak Negative-Pulse Grid-No. 1 Voltage: 330 V
Peak Cathode Current: 550 mA
Average Cathode Current: 175 mA
Plate Dissipation: 17.5 W
Grid-No. 2 Input: 3.5 W
Maximum Bulb Temperature (Hottest Point): 240 °C

Circuit Constraints and Protection

Grid-No. 1-Circuit Resistance: For grid-resistor-bias operation, the maximum allowable resistance is 1.0 MΩ.
Excitation Protection: A bias resistor or other protective circuitry is strictly required to protect the tube from excessive current and thermal damage in the event that the drive excitation is lost.

Average Characteristics Curves

For circuit design and load-line analysis, the average characteristics curves of the 17GJ5A are identical to those of the 6GW6 vacuum tube.

Technical Summary

The 17GJ5A is a robust, high-efficiency Novar beam power pentode designed specifically for television horizontal-deflection-amplifier service. Operating with a 16.8 V, 0.45 A heater, it provides high peak current capabilities (up to 550 mA peak cathode current) and can withstand peak positive plate pulses up to 6,500 V. Its physical design features a compact T-12 envelope with an exhaust tip on the base, and it is available in both standard 9QK pinout and top-cap plate configurations. By adhering to the specified design-maximum ratings and implementing necessary excitation loss protection, the 17GJ5A delivers reliable performance in demanding high-voltage deflection circuits.

Socket description

Novar 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 9QK
Socket code: B9E
Base pins: 9
Nominal heater voltage: 16.8 V
Nominal heater current: 450 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

9QK - 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

Beam Power

X-ray radiationInterelectrode capacitances

Plate resistance: 15000 Ω
Transconductance: 0.0071 S
Amplification factor: 4.4
Max plate voltage: 770 V
Max screen voltage: 220 V
Max plate dissipation: 17.5 W
Max screen dissipation: 3.5 W
Max cathode current: 550 mA

Reference-only sheet; parent electrical ratings not reproduced in supplied source.

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 5 of 7

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

Heater voltage
16.8 V
AC or DC at rated heater current
Heater current
450 mA
Nominal current
Warm-up time
11 s
Average
Reference parent type
6GJ5A
Electrical characteristics same except heater

Data set 02

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

For fixed-bias operation 2.2
2.2 MΩ
Published in approved 17GJ5A target datasheet entry; Section1
For cathode-bias operation 2.2
2.2 MΩ
Published in approved 17GJ5A target datasheet entry; Section1
DC Plate Supply Voltage
770 V
Published in approved 17GJ5A target datasheet entry; Section1
Peak Positive-Pulse Plate Voltage*
6500 V
Published in approved 17GJ5A target datasheet entry; Section1
Peak Negative-Pulse Plate Voltage
1500 V
Published in approved 17GJ5A target datasheet entry; Section1
DC Grid-No.2 Voltage
220 V
Published in approved 17GJ5A target datasheet entry; Section1
DC Grid-No.l Voltage
-55 V
Published in approved 17GJ5A target datasheet entry; Section1
Peak Negative-Pulse Grid-No.l Voltage
330 V
Published in approved 17GJ5A target datasheet entry; Section1
Peak Cathode Current
550 mA
Published in approved 17GJ5A target datasheet entry; Section1
Average Cathode Current
175 mA
Published in approved 17GJ5A target datasheet entry; Section1
Plate Dissipation*
17.5 W
Published in approved 17GJ5A target datasheet entry; Section1
Grid-No.2 Input
3.5 W
Published in approved 17GJ5A target datasheet entry; Section1
For grid-resistor-bias operation*
1 MΩ
Published in approved 17GJ5A target datasheet entry; Section1
# Pulse duration must not exceed 15% of a horizontal scanning cycle (
10 microseconds
Published in approved 17GJ5A target datasheet entry; Section1
Heater Current 4.1 5.6 6.3
8 V
Published in approved 17GJ5A target datasheet entry; Section1
Peak Heater-Cathode 0.6 0.45 0.41
300 mA
Published in approved 17GJ5A target datasheet entry; Section1
Plate-Supply Voltage 600
600 V
Published in approved 17GJ5A target datasheet entry; Section1
DC Plate Voltage 140
275 V
Published in approved 17GJ5A target datasheet entry; Section1
Grid-No.2 (Screen-Grid) Supply Voltage
600 V
Published in approved 17GJ5A target datasheet entry; Section1
DC Grid-No.2 Voltage
275 V
Published in approved 17GJ5A target datasheet entry; Section1
DC Grid-No.l (Control-Grid) Voltage
-50 V
Published in approved 17GJ5A target datasheet entry; Section1
Cathode Current 22
20 mA
Published in approved 17GJ5A target datasheet entry; Section1
Plate Dissipation 1.8
2.4 W
Published in approved 17GJ5A target datasheet entry; Section1
Grid-No.2 Input*
0.55 W
Published in approved 17GJ5A target datasheet entry; Section1
DC Plate Voltage 100
170 V
Published in approved 17GJ5A target datasheet entry; Section1
DC Grid-No.2 Voltage
120 V
Published in approved 17GJ5A target datasheet entry; Section1
DC Grid-No.l Voltage —3
-1.2 V
Published in approved 17GJ5A target datasheet entry; Section1
voltage to
100 V
Published in approved 17GJ5A target datasheet entry; Section1
receivers to
50 V
Published in approved 17GJ5A target datasheet entry; Section1

Characteristic

Heater Voltage (ac/dc) 6.3 12.6
16.8 V
Published in approved 17GJ5A target datasheet entry; Section1
Heater Current 1.2 0.6
450 mA
Published in approved 17GJ5A target datasheet entry; Section1
Heater Warm-up Time (Average) 11
11 seconds
Published in approved 17GJ5A target datasheet entry; Section1
Grid No.l to Plate
0.26 pF
Published in approved 17GJ5A target datasheet entry; Section1
Plate Voltage 150 60
250 V
Published in approved 17GJ5A target datasheet entry; Section1
Grid-No.2 Voltage 150 150
150 V
Published in approved 17GJ5A target datasheet entry; Section1
Grid-No.l Voltage —22.5 0
-22.5 V
Published in approved 17GJ5A target datasheet entry; Section1
Plate Resistance (Approx.)
15000 Ω
Published in approved 17GJ5A target datasheet entry; Section1
Transconductance
7100 µS
Published in approved 17GJ5A target datasheet entry; Section1
390"
70 mA
Published in approved 17GJ5A target datasheet entry; Section1
Grid-No.l Voltage for plate current of
1 mA
Published in approved 17GJ5A target datasheet entry; Section1
Grid-No.l Voltage for plate current of 1 mA
-42 V
Published in approved 17GJ5A target datasheet entry; Section1
Plate Resistance (Approx.)
0.35 MΩ
Published in approved 17GJ5A target datasheet entry; Section1
Plate Current 15
10 mA
Published in approved 17GJ5A target datasheet entry; Section1
Grid-No.2 Current
3 mA
Published in approved 17GJ5A target datasheet entry; Section1
For fixed-bias operation 0.5
1 MΩ
Published in approved 17GJ5A target datasheet entry; Section1
For cathode-bias operation 0.5
2.2 MΩ
Published in approved 17GJ5A target datasheet entry; Section1

Capacitance

Plate to Cathode, Heater, Grid No.2, and Grid No.3
6.5 pF
Published in approved 17GJ5A target datasheet entry; Section1