What is the E186F vacuum tube?

The E186F is a pentode vacuum tube designed for preamp applications. Special Quality frame-grid pentode..

What are the key specifications of the E186F?

Amplification factor μ ≈ 53, transconductance gm ≈ 16.5 mA/V, plate resistance rp ≈ 100.0 kΩ, max plate voltage 210 V, max plate dissipation 3 W, heater 6.3 V / 0.32 A.

Is the E186F still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the E186F as Rare availability. NOS (new-old-stock) examples from RCA, Mullard, Tung-Sol, GE, Sylvania and Telefunken trade among collectors; modern production where it exists comes mostly from JJ Electronic, Electro-Harmonix, Tung-Sol (New Sensor), Genalex, and a handful of small-batch makers.

What does the E186F sound like?

Special Quality frame-grid pentode.. Sonic character also depends heavily on the circuit operating point, the surrounding tubes in the stage, and the output transformer when present — use the interactive loadline calculator on this page to explore the trade-offs.

E186F Pentode Vacuum Tube

Small-signal pentode for low-noise voltage amplification

PentodeHeater 6.3 V · 0.32 A9-pin NovalPhilips 1962

Plate dissipation: 3W
Max plate voltage: 210V
Amplification factor: 53
Transconductance: 16.5mA/V
Plate resistance: 100kΩ

E186F

Characteristics

Datasheet values, once each. Every value cites its sheet.

HeaterIndirectly heated

Specifications of E186F — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.32 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of E186F — Limiting values
Plate voltageVa max	210 V
Screen voltageVg2 max	175 V
Plate dissipationPa max	3 W
Cathode currentIk max	25 mA
Grid resistorRg1 max	250 kΩ
Peak plate voltageVao	400 V

Mechanical

Specifications of E186F — Mechanical
Base	9-pin Noval
Rarity	Rare
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of E186F — Small signal
Transconductance	16.5 mA/V
Plate resistance	100 kΩ
Amplification factor	53

Capacitances

Specifications of E186F — Capacitances
Input	7.6 pF
Grid–plate	0.03 pF
Output	3.45 pF

Charactereditorial reading, not a measurement

Specifications of E186F — Character
Gain	53%
Power	8%
Drive	0%
Linearity	74%

datasheet cited · model or editorial reading · catalogue value, no citation attached yet · nothing invented

Using this tube

Interactive loadline calculator not available for this tube yet — it needs calibrated Koren or Ayumi parameters.

Applications

Voltage amplifier

Generic pentode preamp stage

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : Philips E186F datasheet

Manufacturer datasheets

2 manufacturer datasheets cross-checked for E186F2 verified

E186F DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: Philips E186F datasheet
Reviewed: 2026-05-29
Status: DataModelCalc
Model: under review

Context

The E186F is a indirectly-heated pentode from Philips, introduced around 1962. It provides a gain factor (μ) of 53 with 100.0kΩ plate resistance. Commonly used in preamp applications. Special Quality frame-grid pentode.

History

Introduced: 1962
Manufacturer: Philips
Era: Late Production

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