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AL4 — Power Pentode, P8A | Tubeofile
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AL4
Power Pentode — P8A
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Philips
↗ Radiomuseum
Known Equivalents & Substitutes
No known equivalents. If you know of any, use the ⚑ Report Issue button above.
Similar Tubes (Not Drop-In Compatible)
EL11
Related power pentode — different characteristics
EL33
Octal-base equivalent — different base, not pin-compatible
EL3N
6.3 V heater version — electrically identical except heater, see EL3N for full data and curves
Electrical Specifications
Absolute Maximum
Anode Voltage (max)
Anode Voltage (max)
250
V
Screen Voltage (max)
Screen Voltage (max)
250
V
Anode Dissipation (max)
Anode Dissipation (max)
9
W
Typical Operating
Anode Voltage (typical)
Anode Voltage (typical)
250
V
Screen Voltage (typical)
Screen Voltage (typical)
250
V
Grid 1 Bias Voltage
Grid Bias Voltage
-5.8
V
Anode Current
Anode Current
36
mA
Screen Current
Screen Current
Output
Output Power
Output Power (D=10%, 3rd H.)
3.8
W
Load Impedance
Optimum Load Resistance
8,000
Ω
Heater
Heater Voltage
Heater Voltage
4
V
Heater Current
Heater Current
1.75
A
Notes
For full data and characteristic curves, see type EL3N (per Philips datasheet).
The 'A' prefix in the Philips naming convention indicates a 4 V heater tube.
P8A side-contact base ('Sockel: P').
Heater: Vf = 4.0 V, If = 1.75 A, indirect, parallel supply.
Pin Layout — P8A
1
2
3
4
5
6
7
8
1
Suppressor Grid (g3)
2
Screen Grid (g2)
3
Control Grid (g1)
4
References
https://frank.pocnet.net/sheets/030/a/AL4.pdf
5
mA
Anode Resistance
Anode Impedance
50,000
Ω
Transconductance
Transconductance
9.5
mA/V
Cathode Resistor (self-bias)
Cathode Bias Resistor
145
Ω
Cathode
5
Heater
6
Heater
7
Metallization
8
No Connection
TC
Top Cap —
Anode (top cap)