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24A

Indirectly heated screen-grid tetrode chiefly intended for high-frequency receiver amplification, with manufacturer documentation also supporting detector and audio-frequency voltage-amplifier service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 5E
Socket code: UX5
Base pins: 5
Nominal heater: 2.5 V / 1.75 A

Description

Sylvania Type 24A is an indirectly heated screen-grid high-frequency amplifier tetrode, chiefly intended as a replacement tube for older receivers; it may also be used for audio-frequency amplification or detector service.

Socket description

Small 5-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 5E
Socket code: UX5
Base pins: 5
Nominal heater voltage: 2.5 V
Nominal heater current: 1.75 A
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

5E - 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

Tetrode

X-ray radiationInterelectrode capacitances

Plate resistance: 600000 Ω
Transconductance: 0.0010249999999999999 S
Max plate voltage: 250 V
Max screen voltage: 90 V

Published ratings and characteristics promoted from the approved 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.

Data set 01

1932 Cunningham Radio Tubes

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

Grid-plate capacitance
0.01 pF
Published direct interelectrode capacitance

Data set 02

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

Mzzzmg: Maximum Screen Voltage
90 V
Published ratings

Capacitance

UUU”” k*'w Grid to Plate
0.007
Published capacitance
Output
10.5
Published capacitance
Plate Voltage
180 V
Published capacitance; Column1
Plate Voltage
25 V
Published capacitance; Column2
Screen Voltage
90 V
Published capacitance; Column1
Screen Voltage
0 V
Published capacitance; Column2
Plate Resistance
0.4
Published capacitance; Column1
Plate Resistance
0.6
Published capacitance; Column2
Transconductance
1000 uS
Published capacitance; Column1
Transconductance
1080 uS
Published capacitance; Column2
Plate Current
4 mA
Published capacitance; Column1
Plate Current
4 mA
Published capacitance; Column2
Screen Current
1.7 mA
Published capacitance; Column1
Screen Current
1.7 mA
Published capacitance; Column2
Plate Voltage
250 V
Published capacitance
Screen Voltage
20 V
Published capacitance; Column1
Screen Voltage
45 V
Published capacitance; Column2
Plate Current Adjusted to
0.1 mA
Published capacitance
Plate Voltage
180 V
Published capacitance

Data set 03

193X Cunningham

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristics

Heater/filament voltage
2.5 V
Published nominal
Heater/filament current
1.75 A
Published nominal
Transconductance
1050 uS
Published characteristic

Data set 04

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

The
24
The 24-A is a screen-grid amplifier
amplifier in a-c receivers. The
24
amplifier in a-c receivers. The 24-A
HeaTeR VOLTAGE (A. C.or D. C)......oovena e
2.5 V
HeaTeR VOLTAGE (A. C.or D. C)......oovena e 2.5 Volts
HEATER CUBRENT ...oivivvinnnncnnnennenaneans
1.75 A
HEATER CUBRENT ...oivivvinnnncnnnennenaneans 1.75 Amperes
PLATE VOLTAGE* ......coivivieneinneennn
250 V
PLATE VOLTAGE* ......coivivieneinneennn 180 250 Volts
ScREEN VOLTAGE (Grid No
90 V
ScREEN VOLTAGE (Grid No. 2)........... 90 max. 90 max. Volts
GRD VOLTAGE (Grid No
-3 V
GRD VOLTAGE (Grid No. 1)......ccvnu.s. -3 -3 Volts
PLATE CURRENT ...vviveeceonnnennanans
4
PLATE CURRENT ...vviveeceonnnennanans 4 4 Milliamperes
ScREeN CURRENT (Maximum}
1.7
ScREeN CURRENT (Maximum}............ 1.7 1.7 Milliamperes
AMPLIFICATION FACTOR
630
AMPLIFICATION FACTOR ................. 400 630
* Maximum plate voltage =
275 V
* Maximum plate voltage = 275 volts,
connection, refer to type
24
connection, refer to type 2A5. The screen voltage for the 24-A may be obtained
E£=
2.5 V
E£=2.5 VOLTS
| SCREEN voLTs =
90 V
| SCREEN voLTs =90
PLATE VOLTS
76 V
PLATE VOLTS 92C~S576R3

Characteristic

PLATE RESISTANCE ....vvvveeneninnanens
0.6
PLATE RESISTANCE ....vvvveeneninnanens 0.4 0.6 Megohm
TRANSCONDUCTANCE +vvvuevsoonns eeane
1050 µS
TRANSCONDUCTANCE +vvvuevsoonns eeane 1000 1050 Micromhos

Data set 05

1948 Brimar Radio Valve Manual

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

HeaterOrFilamentVoltage
2.5 V
HeaterOrFilamentCurrent
1.75 A

Data set 06

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

Plate Voltage
250 V
Screen Voltage
90 V
Screen Current
1.7 mA

Characteristic

Plate Current
4 mA
Plate Resistance
0.6 Mohm
Transconductance
1050 uS

Data set 07

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristics

Input capacitance
5.3 pF
Output capacitance
10.5 pF
Grid-to-plate capacitance
0.007 pF
Plate resistance
600000 ohm
ClassA; OperatingPoint1
Transconductance
1050 uS
ClassA; OperatingPoint1

Other

Plate voltage
250 V
ClassA; OperatingPoint1
Screen voltage
90 V
ClassA; OperatingPoint1
Control-grid bias
3 V
ClassA; OperatingPoint1
Plate current
4 mA
ClassA; OperatingPoint1
Screen current
1.7 mA
ClassA; OperatingPoint1
Maximum plate voltage
250 V
Maximum screen voltage
90 V