E186F — Small Signal Pentode, Noval | Tubeofile | Tubeofile

E186F

Name: E186F
Brand: Philips

Small Signal Pentode — Noval — Philips

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

7737

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)210V

Screen Voltage (max)Screen Voltage (max)175V

Anode Dissipation (max)Anode Dissipation (max)3W

Screen Dissipation (max)Screen Dissipation (max)0.7W

Cathode Current (max)

Notes

The datasheet operating conditions use a positive grid No.1 supply (+Vbg1 = 9 V) with a cathode resistor (Rk = 630 Ω). The effective grid-cathode bias is approximately −1.3 V (Vgk = +9 − Ik×Rk ≈ +9 − 10.3 = −1.3 V).
Pin 8 (g3/suppressor) is internally connected to cathode. Pin 6 is an internal connection (shield).
Pins 1 and 3 are both cathode connections — connect both for proper operation.
Vkf_max = 60 V (absolute limit); 70 V applied during 10,000-hour life test with cathode negative. Use the 60 V figure for circuit design.
Rg1_max: 0.25 MΩ with fixed bias, 0.5 MΩ with automatic (cathode) bias.
Heater voltage must be held within 6.0–6.6 V; variation beyond this range shortens tube life.
Equivalent noise resistance Req = 330 Ω at 45 MHz — an RF/wideband noise parameter, not comparable to audio equivalent input noise voltage (µV).
The S.Q. (Special Quality) designation indicates enhanced mechanical and electrical screening to NATO/IEC standards: 500 g shock, 2.5 g/50 Hz vibration, 10,000-hour life test.
The designation 'EF186F' sometimes seen in secondary sources is a misreading of 'E186F' (the correct Philips/IEC designation). The 'E' prefix denotes 6.3V indirectly heated cathode; 'F' suffix denotes pentode. The tube has no relation to the EF86 family.
7737 is the Amperex (US) equivalent designation confirmed in Philips interchange guide.

Pin Layout — Noval

1Cathode

2Control Grid

3Cathode

Socket-Compatible Tubes ⚠ Not electrically compatible

6P33P 6P43P 7189A 8BQ5 AL860 D3a E180F EL803 EL84 EL85 PL84 UEL84

References