Basing (pinout)
Bottom view — the socket as you see it from the wiring side. Hover, tap, or focus a pin to name it. Read from the datasheet basing diagram (how to read these →).
Hover, tap, or focus a pin to name it.
- High voltage (B+)
- Control grid
- Cathode
- Heater / filament
- Internal connection
Viewed from below (socket / wiring side) · noval 9-pin (B9A) · basing —
⚡ Oxblood pins sit at B+ — hundreds of volts in service, lethal, and still charged after power-off.
Datasheets
Primary manufacturer data, via public tube-data archives. The model below is fitted to the tabulated "average characteristics" in these sheets; the datasheet files themselves are linked, never rehosted.
| Publisher | Type | Source |
|---|---|---|
| Philips / Mullard | EF86 | frank.pocnet.net ↗ |
| Philips | EF86 (1956 issue) | frank.pocnet.net ↗ |
Circuit Codex model
A CC0 ngspice model in the Koren form, fitted here to the published anchor — no parameters copied from other model collections. Methodology →
- Anchor
- Va=250 V, Vg2=140 V, Vg3=0 V, Vg1=-2.2 V → Ia=3.0 mA, Ig2=0.6 mA, gm=2200 µmho
- Source
- Philips/Mullard EF86 data sheet, January 1970 (A.F. Pentode), typical characteristics
- Note
- µ is the grid-No.1-to-grid-No.2 amplification factor (38), the tabulated amplification factor on the same typical-characteristics row as Ia/Ig2/gm; the sheet prints Ri=2.5 MΩ alongside. Ig2 is tabulated at the plate/gm point, so KG1 and KG2 both anchor there. EX=1.5 and KVB=30 (pentode) are project defaults per METHODOLOGY.md. Note that Philips' earlier (1956) issue of the same sheet prints the typical point as Vg1=-2 V, S=2.0 mA/V with identical Ia/Ig2/µ/Ri; the 1970 issue's -2.2 V / 2.2 mA/V figures are the ones fitted.
- File
- models/ef86.inc ↗
See these parameters drawn: the load line explorer plots the EF86's plate-curve family from this model and solves an operating point on it.
Maximum ratings
Limiting values under the design-centre rating system. One watt of anode dissipation and a 6 mA cathode ceiling put this valve firmly in small-signal service — it is a pentode, but it is not an output pentode, and the AC15 works it at a couple of milliamps. The unusually generous grid-No.1 circuit resistance is the tell of a valve designed for a high-impedance input stage.
- Anode voltage, no current
- 550 V
- Anode voltage
- 300 V
- Anode dissipation
- 1 W
- Grid No.2 voltage, no current
- 550 V
- Grid No.2 voltage
- 200 V
- Grid No.2 dissipation
- 0.2 W
- Cathode current
- 6 mA
- Grid-No.1 circuit resistor
- 10 MΩ if Wa < 0.2 W · 3 MΩ if Wa > 0.2 W · 22 MΩ with grid-current biasing
- Cathode-to-heater voltage
- 100 V cathode positive · 50 V cathode negative
- Rating system
- Design centre — carries an allowance for manufacturing spread
- Source
- Philips EF86 data sheet, January 1970 — limiting values (design-centre rating system) ↗