8BA8A

      The 8BA8A is a miniature,medium mu triode and sharp cutoff pentode.The triode section is intended for use as a sync separator and the pentode section as a video amplifier.The pentode section features a controlled plate knee characteristic.The 6BA8A incorporates a 600 ma heater and controlled heater warm-up time for operation in television receivers employing a series heater string.The 8BA8A is identical to the 6BA8A except for heater characteristics.
      Here you can get some information about the 8BA8A heater characteristics.The heater voltage is 8.4 V.The heater current is 450 Ma.The heater warm-up time is 11 seconds.Then is about the heater-cathode voltage.The maximum of 8BA8A heater negative with respect to cathode (Total DC and Peak) is 200 V;the maximum heater negative with respect to cathode (DC) is 100 V and the maximum heater negative with respect to cathode (Total DC and Peak) is 200 V.
      The following is about the ratings of 8BA8A (Design Center Values).The maximum plate voltage of triode and pentode are both 300 V.The maximum grid No.2 supply voltage of pentode is 300 V.The plate dissipation of triode is 2.0 and the plate dissipation of pentode is 3.25 W.The maximum grid NO.2 dissipation of pentode is 1.0 W.The maximum negative grid NO.1 voltage of pentode is 50 V.The maximum positive grid NO.1 voltage of pentode is 0 V.Next is about the maximum grid NO.1 circuit resistance.The fixed bias of triode is 0.5 megohm and of pentode is 0.25 megohm;the self bias of triode and pentode are both 1.0 megohm.
      The last one is about the characteristics and typical operation of class A1 amplifier 8BA8A.The plate voltage of triode and pentode are both 200 V.The grid No.2 voltage of pentode is 150 V.The grid No.1 voltage of pentode is 0 V and triode is -8 V.The cathode bias resistor of pentode is 180 ohms.The plate current of triode is 8.0 Ma and of pentode is 13 Ma.The grid NO.2 current of pentode is 3.5 Ma.The transconductance of of triode is 2700mhos and of pentode is 9000 mhos.The amplification factor of triode is 18.The plate resistance (approx.) of  triode is 6700mhos and of pentode is 400,000 mhos.The grid NO.1 voltage for Ib=10 a (approx.) of  triode is -16 V and of pentode is -10 V.Under the condition of Eb=65 V,Ec2=150 V,the plate current of pentode is 42 Ma and the grid NO.2 current of pentode is 12.5 Ma.