TUBE: EL33
SOURCE FILE: sheets/154/e/EL33.pdf
MANUFACTURER: Mullard (ISSUE 2; code EL33 1546) — different print run of same Mullard data as 858
YEAR: n/a (Issue 2)
TYPE (per PDF): OUTPUT PENTODE (High-sensitivity output pentode for A.C. mains equipment)
PAGES: 10 (page1-2 data, pages 3-10 = curves only)

===== PAGE 1 =====
OUTPUT PENTODE — EL33 (Mullard)
HEATER: Vb(Vh) = 6.3 V ; Ih = 0.9 A
CAPACITANCE: c(a-g1) = 1.0 µµF

OPERATING CONDITIONS AS CLASS 'A' AMPLIFIER:
  Va = 250 V ; Vg2 = 250 V ; Ia = 36 mA ; Vg1 = -6 V ; Ig2 = 4 mA
  gm = 9 mA/V ; ra = 50,000 ohms ; µ(g1g2) = 23
  Wout = 4.5 W ; Ra = 7,000 ohms
  Vin(rms) = 4.2 V ; Vin(rms)(50mW) = 0.33 V ; Dtot = 10 % ; Rk = 150 ohms

OPERATING CONDITIONS FOR TWO VALVES IN PUSH-PULL:
  Va = 250 V ; Vg2 = 250 V
  Iao = 2x24 mA ; Ia max = 2x28.5 mA
  Ig2o = 2x2.8 mA ; Ig2 max = 2x4.6 mA
  Rk = 140 ohms ; Ra(anode to anode) = 10,000 ohms
  Wout = 8.2 W ; Vin(rms) = 6.7 V ; Dtot = 3.1 %

OPERATING CONDITIONS AS TRIODE (g2 connected to a):
  Va = 250 V ; Ia = 20 mA ; Vg = -8.5 V
  gm = 6.5 mA/V ; µ = 20 ; ra = 3,000 ohms
  Rk = 425 ohms ; Ra = 7,000 ohms
  Wout = 1.1 W ; Dtot = 5 % ; Vin(rms) = 5.9 V ; Vin(rms)(50mW) = 1.1 V

FOOTER: ISSUE 2 — Mullard — EL33 1546/1

===== PAGE 2 =====
EL33 — OUTPUT PENTODE (Mullard)
LIMITING VALUES:
  Va(b) max = 550 V
  Va max = 250 V
  Wa max = 9 W
  Vg2(b) max = 550 V
  Vg2 max = 275 V
  Wg2 max (zero sig.) = 1.2 W
  Wg2 max (max. sig.) = 2.5 W
  Ik max = 55 mA
  Vg1 max (Ig1=0.3µA) = -1.3 V
  R(g1-a) max = 1 megohm  [note: printed g1-a, equivalent to Rg1-k=1MΩ]
  Vh-k max = 50 V
  Rh-k max = 5,000 ohms
ARRANGEMENT OF ELECTRODES AND BASE CONNECTIONS — OCTAL BASE:
  a=top; grids g3,g2,g1; k,h,h at base. Dimensions 46 mm max dia, 126 mm max height.

FOOTER: ISSUE 2 — Mullard — EL33 1546/2

===== PAGE 3 =====
[courbes seules — pas de données tabulaires] Ia & Ig2 vs Vg1 at Va=Vg2=250V.

===== PAGE 4 =====
[courbes seules — pas de données tabulaires] Ia vs Va family (Vg1 0 to -12V), Vg2=250V, load lines Wa=9W / Ra=7000Ω.

===== PAGE 5 =====
[courbes seules — pas de données tabulaires] Distortion D2/D3/Dtot & Vin vs Wout, SE class A, Rk=150Ω.

===== PAGE 6 =====
[courbes seules — pas de données tabulaires] Vin/Wout/Ia/Rk vs Vg2 (200-260V), Va=(Vg2-15V).

===== PAGE 7 =====
[courbes seules — pas de données tabulaires] Vin/Wout/Ia/Rk vs Vg2 (250-270V), Va=250V.

===== PAGE 8 =====
[courbes seules — pas de données tabulaires] Push-pull distortion/Vin/Ia/Ig2 vs Wout, Va=Vg2=250V, Iao=2x24mA, Ra=10000Ω, Rk=140Ω.

===== PAGE 9 =====
[courbes seules — pas de données tabulaires] Ia vs Vg1 transfer at Va=250V.

===== PAGE 10 =====
[courbes seules — pas de données tabulaires] Ia vs Va family with Vg1 steps, Ra=7000Ω load line, Wa=9W.

NOTE: Same numeric data as Mullard 858 sheet (129/e). Confirms PENTODE. Va max=250V, Vg2 max=275V, Vh-k=50V.