TUBE: EL37
SOURCE FILE: sheets/129/e/EL37.pdf
FABRICANT: Mullard
ANNEE: ISSUE 4 (codes 157/473/858)
LANGUE: en

===== PAGE 1 =====
EL37 - OUTPUT PENTODE
25-watt pentode, particularly suitable for use in push-pull combination for
outputs up to 69W, or as drivers for large power triode push-pull output stage.
HEATER
  Vh   6.3 V
  Ih   1.4 A
CAPACITANCES
  Cout    9.0  pF   (Cak)
  Cin    17.5  pF   (Cgk)
  Ca-g1   1.0  pF   (Cga)
OPERATING CONDITIONS AS PENTODE
  Va    250 V
  Vg2   250 V
  Vg1  -13.5 V
  Ia    100 mA
  Ig2   13.5 mA
  Rk    120 Ohm
  gm    11 mA/V
  ra    13.5 kOhm
  mu g1-g2  10
  Ra    2.5 kOhm
  Vin(rms) (Pout=50mW)  0.45 V
  Pout (Dtot=10%)       10.5 W
  Vin(rms) (start of Ig1) 10.8 V
  Dtot (start of Ig1)   13.5 %
  Pout (start of Ig1)   11.5 W
OPERATING CONDITIONS - TWO VALVES IN PUSH-PULL (Self Bias)
  Va        250      325    V
  Vg2       250      325    V
  Ia(0)    2x59     2x77    mA
  Ia(max sig) 2x68  2x90    mA
  Ig2(0)   2x7.5    2x9.75  mA
  Ig2(max sig) 2x18 2x30    mA
  Rk        130      130    Ohm
  Ra-a      4.0      4.0    kOhm
  Pout       20       35    W
  Vin(g1-g1)(rms) 29   43   V
  Dtot      2.25     4.4    %

===== PAGE 2 =====
OPERATING CONDITIONS - TWO VALVES IN PUSH-PULL (Fixed Bias)
  Va        350      400    V
  Vg2       350      400    V
  Ia(0)    2x40     2x50    mA
  Ia(max sig) 2x118 2x138   mA
  Ig2(0)   2x5      2x6     mA
  Ig2(max sig) 2x29 2x36    mA
  Vg1       -31      -36    V
  Ra-a      3.25     3.25   kOhm
  Pout       46       69    W
  Vin(g1-g1)(rms) 43.4  49  V
  Dtot      2.8      2.5    %
OPERATING CONDITIONS AS SINGLE VALVE, TRIODE CONNECTED (Grid2 to anode via 100 Ohm)
  Va        300      400    V
  Ia         50      37.5   mA
  Vg1       -26      -39    V
  gm        6.5      4.5    mA/V
  mu        9.0      9.0    -
  ra        1.4      2.0    kOhm
OPERATING CONDITIONS AS PUSH-PULL PAIR, TRIODE CONNECTED (Self Bias)
  Vb        350      435    V
  Va        320      400    V
  Ia+g2(0) 2x56     2x70    mA
  Ia+g2(max sig) 2x64 2x80  mA
  Pa+g2    2x18     2x28    W
  Rk        245      245    Ohm
  Ra-a      4.0      4.0    kOhm
  Vin(rms) 2x21.5   2x27.2  V
  Pout      12.5     20.6   W
  Dtot      4.1      4.3    %
LIMITING VALUES - PENTODE CONNECTED
  Va(b) max.       800   V
  Va max.          400   V
  Vg2(b) max.      800   V
  Vg2 max.         400   V
  Vg1 max. (Ig1=+0.3uA) -1.3 V
  Vh-k max.         75   V
  Rh-k max.        5.0   kOhm

===== PAGE 3 =====
EL37 (cont.)
  Rg1-k max. (cathode bias)  500 kOhm
  Rg1-k max. (fixed bias)    100 kOhm
  pa max.          25   W
  pg2 max.         6.0  W
  Ik max.          200  mA
LIMITING VALUES - TRIODE CONNECTED (NORMAL APPLICATIONS)
  Va+g2 max.       400  V
  pa+g2 max.       28   W
LIMITING VALUES - TRIODE CONNECTED (IN CATHODE-COUPLED PP DRIVER STAGE FOR LARGE POWER TRIODES)
  Va+g2 max.       500  V
  pa+g2 max.       12.5 W
OCTAL BASE - electrode arrangement:
  a=top ; g2 and g1 (side) ; h h = heater ; k,g3 (cathode+suppressor common)
  pinout (octal): a, g2, g1, h, h, k+g3 (suppressor g3 internally tied to cathode)
  Dimensions: 54 mm max dia ; 131 mm max height

===== PAGE 4 =====
[courbes seules] EL37: Ia vs Va for Vg2=250V, Vg1=0 to -27V

===== PAGE 5 =====
[courbes seules - NOTE: PDF page 5 in 129/e is actually a duplicate of curve at Vg2=250V (Ia-Va), 858-4]
[Note: 129/e n'a que 4 pages dans cet exemplaire ; pages courbes supplementaires presentes dans 154/e]