12AT7C is double triode small size novel tube,it is used as voltage magnification in amplifying circuit and inverter drive push-pull amplifier.

Uf---------------------6.3(并) 12.6(串) V
If----------------------------0.30 0.15 A

Direct Interelectrode Capacitances
grid to grid----------0.005 PF
plate to plate-------------------0.4 PF
grid to plate(single triode) -------1.5 PF
grid to cathode and filament(single triode)------2.2 PF
plate to cathode and filament(single triode)------0.5 PF
filament to cathode(single triode) -----------2.4 PF
palte to cathode(single triode)-----------0.2 PF
cathode to filament and grid(single triode) -----4.6 PF
plate to filament and grid(single triode)------1.8 PF

static parameter

Ua--------------------100 250 V
Ia---------------------3.7 10 mA
Gm--------------------4 5.5 mA/V
Rk---------------------270 200 Ω
u----------------------60 60
ri(approx)---------------15 10.9 KΩ
Ug(approx)--------------—5 —12 V
(when la=10Ua)

class A1.maximum.single triode.

Ua-----------------300 V                                                                                                                                                                                             

  Pa--------- 2.5 W                                                                                                                                                                                                     

   Ug----------------—50 V
Uh-k(pk)--------±90 V
with cathode bias  --------------1 MΩ
with fixed bias ----------0.25 MΩ