TUBEOFILE
Search
Compare
FAQ
Tube+
Sign In
Sign In
☰
Loading...
25E5 — Power Pentode, Octal | Tubeofile | Tubeofile
← Browse
25E5
Power Pentode — Octal
···
+ Compare
⚡ Roll
⤺ Replace
Data: High
High quality — base, heater, all universal parameters present, and ≥50% of desirable parameters filled in. Safe to use for design decisions.
↗ TDSL
↗ Radiomuseum
Known Equivalents & Substitutes
PL36
Similar Tubes (Not Drop-In Compatible)
6CM5
American designation for EL36 (6.3V heater) — not a drop-in in 25V circuits
EL36
Electrically identical but 6.3V/1.25A heater — not a drop-in in 25V series heater circuits
Electrical Specifications
Section 1 — Pentode
Absolute Maximum
Anode Voltage (max)
Anode Voltage (max)
250
V
Screen Voltage (max)
Screen Voltage (max)
250
V
Anode Dissipation (max)
Anode Dissipation (max)
12
W
Screen Dissipation (max)
Screen Dissipation (max)
5
W
Notes
25V heater version of the EL36/6CM5, designed for series-string heater circuits. Heater current is 0.3A at 25V.
GE Essential Characteristics confirms: 25V/0.3A heater, Octal (8GT) base, beam power amplifier, Pa_max=10W, Va_max=250V, Vs_max=250V, Va=250V, Vs=250V, Vg=18V (cathode bias), Ia=35mA.
SAMs substitution guide lists 30P4 and PCF805 as substitutes.
Brans Vademecum groups 25E5 with EL36, EL81, EL82, PL82, and many other line-output pentode types.
The PL36 is the European designation for the same tube (P-series = 300mA heater).
Top-cap anode connection provides the high-voltage insulation needed for TV horizontal deflection service.
Pin Layout — Octal
1
2
3
4
5
6
7
8
1
Internal Connection
2
Internal Connection (Cathode/Suppressor)
3
Heater
4
Socket-Compatible Tubes
⚠ Not electrically compatible
EL36
References
https://frank.pocnet.net/sheets/030/e/EL36.pdf
Cathode Current (max)
Cathode Current (max)
200
mA
Heater-to-Cathode Voltage (max)
Heater-to-Cathode Voltage (max)
100
V
Max Grid Resistor
Max Grid Resistor
0.5
MΩ
Typical Operating
Anode Voltage (typical)
Anode Voltage (typical)
100
V
Screen Voltage (typical)
Screen Voltage (typical)
100
V
Grid 1 Bias Voltage
Grid 1 Bias Voltage
-8.2
V
Anode Current
Anode Current
100
mA
Screen Current
Screen Current
7
mA
Anode Resistance
Anode Resistance
5,000
Ω
Transconductance
Transconductance
14
mA/V
Output
Output Power
Output Power (Class B PP)
44.5
W
Load Impedance
Load Impedance (Class B PP)
3,500
Ω
Capacitances
Grid-to-Plate Capacitance
Grid-to-Plate Capacitance
1.1
pF
Grid-to-Cathode Capacitance
Grid-to-Cathode Capacitance
17.5
pF
Anode-to-Cathode Capacitance
Anode-to-Cathode Capacitance
8
pF
Section 2 — Triode Strapped
Absolute Maximum
Anode Voltage (max)
Anode Voltage (max)
250
V
Anode Dissipation (max)
Anode Dissipation (max)
13
W
Cathode Current (max)
Cathode Current (max)
200
mA
Typical Operating
Anode Voltage (typical)
Anode Voltage
375
V
Anode Current
Anode Current
50
mA
Anode Resistance
Anode Resistance
800
Ω
Transconductance
Transconductance
6.8
mA/V
Amplification Factor (μ)
Amplification Factor (μ)
5
—
Output
Output Power
Output Power (SE Class A)
7.8
W
Load Impedance
Load Impedance (SE Class A)
6,400
Ω
Heater
Heater Voltage
Heater Voltage
25
V
Heater Current
Heater Current
0.3
A
Internal Connection (Cathode/Suppressor)
5
Screen Grid (g2)
6
Control Grid (g1)
7
No Connection
8
Heater
TC
Top Cap —
Anode (Top Cap)