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EF95 — Small Signal Pentode, B7G | Tubeofile | Tubeofile

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EF95

Name: EF95
Brand: Mullard

Small Signal Pentode — B7G — Mullard

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Data: HighHigh quality — base, heater, all universal parameters present, and ≥50% of desirable parameters filled in. Safe to use for design decisions.

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Known Equivalents & Substitutes

6AK55654CV850M810060696J1PM056F32E95F408A5743

Electrical Specifications

Section 1 — Pentode

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)180V

Screen Voltage (max)Screen Voltage (max)140V

Anode Dissipation (max)Anode Dissipation (max)1.7W

Screen Dissipation (max)Screen Dissipation (max)0.5W

Notes

Suppressor grid (g3) is internally connected to cathode.
Pin 7 (cathode) and pin 2 (cathode) are connected internally — both must be grounded for proper shielding.
Vs_max from Mullard is 140 V (design centre), while RCA rates the 6AK5 screen at 180 V max. The Mullard 140 V figure is used here as the conservative rating.
Pg2 max depends on screen voltage: 0.5 W for Vg2 up to 90 V (RCA), 500 mW design centre (Mullard).
M8100 and 5654 are special-quality (ruggedised/selected) versions; CV850 is the UK military designation.
Triode connection data is from the Mullard datasheet (page D1). Schlangen measured slightly lower values (μ=30, gm=6.0 mA/V, ra=5.0 kΩ).
Capacitance values listed are for shielded operation (external shield connected to cathode per B7G base).

Pin Layout — B7G

1Control Grid

2Cathode

3Heater

Socket-Compatible Tubes ⚠ Not electrically compatible

6AF4 6AG5 6BJ6 6CG6

References

https://frank.pocnet.net/sheets/129/e/EF95.pdf
https://frank.pocnet.net/sheets/049/6/6AK5.pdf

Cathode Current (max)

18mA

Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)120V

Max Grid ResistorMax Grid Resistor3MΩ

Typical Operating

Anode Voltage (typical)Anode Voltage180V

Screen Voltage (typical)Screen Voltage120V

Grid 1 Bias VoltageGrid 1 Bias Voltage-2V

Anode CurrentAnode Current7.7mA

Screen CurrentScreen Current2.4mA

Anode ResistanceAnode Resistance400,000Ω

TransconductanceTransconductance5.1mA/V

Capacitances

Grid-to-Plate CapacitanceGrid-to-Plate Capacitance (shielded)<0.02pF

Grid-to-Cathode CapacitanceGrid-to-Cathode Capacitance (shielded)4pF

Anode-to-Cathode CapacitanceAnode-to-Cathode Capacitance (shielded)3.1pF

other

Vg(b) max (Boosted Screen Voltage)Vg(b) max (Boosted Screen Voltage)300V

Va(b) max (Boosted Anode Voltage)Va(b) max (Boosted Anode Voltage)300V

rg1 (Grid Input Resistance at 50 Mc/s)rg1 (Grid Input Resistance at 50 Mc/s)25,000Ω

Req (Equivalent Noise Resistance)Req (Equivalent Noise Resistance)2,000Ω

μg2g1μg2g135—

-Vg1 max (Grid 1 Bias max)-Vg1 max (Grid 1 Bias max)50V

Section 2 — Triode Strapped

Absolute Maximum

Anode Dissipation (max)Anode Dissipation (max)1.7W

Cathode Current (max)Cathode Current (max)18mA

Typical Operating

Anode Voltage (typical)Anode Voltage120V

Grid 1 Bias VoltageGrid 1 Bias Voltage-2V

Anode CurrentAnode Current10mA

Anode ResistanceAnode Resistance5,200Ω

TransconductanceTransconductance6.8mA/V

Amplification Factor (μ)Amplification Factor (μ)35—

other

Req (Equivalent Noise Resistance)Req (Equivalent Noise Resistance)900Ω

Heater

Heater VoltageHeater Voltage6.3V

Heater CurrentHeater Current0.175A

Heater

5Anode

6Screen Grid

7Cathode,Suppressor Grid (g3 internal)