Rectifier - Damper Diode ·Rectifier
Series-heater half-wave damper rectifier for television horizontal-deflection service, designed for high pulse current and inverse voltage in sweep-energy recovery.
The 25W4GT is an indirectly heated half-wave rectifier designed for damping-diode service in direct-drive television sweep circuits, with high inverse-voltage and pulse-current capability.
International Octal
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
| Terminal | Section | Connection | Evidence |
|---|---|---|---|
| PIN1IC | — | IC EIA chart transcription; independent manufacturer corroboration pending | Unverified EIA Base Connections, printed page 127, 4CG |
| PIN2IC | — | IC EIA chart transcription; independent manufacturer corroboration pending | Unverified EIA Base Connections, printed page 127, 4CG |
| PIN3K | A | K — Cathode EIA chart transcription; independent manufacturer corroboration pending | Unverified EIA Base Connections, printed page 127, 4CG |
| PIN5P | A | P — Plate (Anode) EIA chart transcription; independent manufacturer corroboration pending | Unverified EIA Base Connections, printed page 127, 4CG |
| PIN7H | — | H — Heater EIA chart transcription; independent manufacturer corroboration pending | Unverified EIA Base Connections, printed page 127, 4CG |
| PIN8H | — | H — Heater EIA chart transcription; independent manufacturer corroboration pending | Unverified EIA Base Connections, printed page 127, 4CG |
1 physical section, each with unique specifications.
Section 1
Damper-service maximum ratings and average voltage drop mapped from the printed shared table.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Heater/filament voltage
25 V
Published heater/filament rating
Heater/filament current
300 mA
Published heater/filament rating
Tube voltage drop
21 V
At 350 mA DC
DC output current
125 mA
TVDamperService
Peak inverse voltage
3850 V
TVDamperService
Peak current
750 mA
TVDamperService
Data set 02
Published operating points and test conditions from this source.
Heater voltage
25 V
Nominal
Heater current
300 mA
Nominal
Maximum DC plate current
125 mA
DamperService
Maximum steady-state peak current
750 mA
DamperService
Heater-cathode voltage, heater negative, DC
500 V
DamperService
Heater-cathode voltage, heater positive, total DC and peak
200 V
DamperService
Tube voltage drop at 250 mA
21 V
DamperService
Heater to cathode
1 pF
Direct interelectrode capacitance
Plate to cathode and heater
6 pF
Direct interelectrode capacitance
Cathode to plate and heater
17 pF
Direct interelectrode capacitance
Data set 03
Published operating points and test conditions from this source.
Heater Voltage
25 V
Heater Current
300 mA
Voltage Drop
32 V
PlateCurrent=250mA
Heater-to-Cathode Capacitance
7 pF
Plate-to-Cathode-and-Heater Capacitance
6 pF
Cathode-to-Plate-and-Heater Capacitance
13 pF
Peak Inverse Voltage
3850 V
DamperService
Peak Plate Current
750 mA
DC Plate Current
125 mA
Plate Dissipation
4.8 W
Maximum Heater-Cathode Voltage Cathode Positive
2300 V
TotalDCPlusPeak
Data set 04
Published operating points and test conditions from this source.
Peak inverse plate voltage
3850 V
HorizontalDeflection
Plate dissipation
3.5 W
WholeTube
Steady-state peak current
750 mA
WholeTube
DC plate current
125 mA
WholeTube
Tube voltage drop at 250 mA
21 V
Characteristic
Heater-to-cathode capacitance
11 pF
WholeTube
Plate-to-cathode-and-heater capacitance
6 pF
WholeTube
Cathode-to-plate-and-heater capacitance
17 pF
WholeTube
Data set 05
Published operating points and test conditions from this source.
Cathode to Plate and Heater Capacitance
17 pF
Plate to Cathode and Heater Capacitance
6 pF