EL34b Vacuum Tube/ Electron Tube/ Audio Tube

High capability audio frequency output pentode tube's anticathode limit dissipation power is 25W. In audio frequency amplifier, if single tube is used to amplify A1, the output power will larger than 10W; If two tubes are used to amplify AB1, the output power will larger than 35W.

EL34 is the same with 6CA7, and can be exchanged each other.
Heater heating
UH: 6.3 V
IH: 1.5 A
Limit rating
Plate voltage: 800 V
Second grid voltage: 500 V
First grid voltage: -100 V
Plate dissipation power: 25 W
Second grid dissipation power: 8 W
Cathode current: 150 mA

First grid resistance
When it is self-partial voltage: 0.7 Mn
When it is fixup partial voltage: 0.5 Mn
Heatervoltage between cathodes: 100 V
Temperature of glass crust: 250
Capacitance between poles
Input capacitance: 15.2 PF
Output capacitance: 8.4 PF
Transroute capacitance: 1.1 PF
First grid heater capacitance: 1.0 PF
Heater shade capacitance between poles: 10 PF

Static state parameter
Ua: 250 V
Ug2: 250 V
Ug3: 0 V
-Ug1: 12.2 V
Ia: 100 mA
Gm: 11 mA/v
Ri: 15 kn
U: G1-g2 11

Commend working state(reference value)
Single tube A1 amplify (fixuppartial voltage)
Ua(b): 265 265 V
Ua: 250 250 V
Ug2: Rg2=2k Rg2=0
Ug3: 0 0 V
-Ug1: 14.5 13.5 V
Ia(0): 70 100 mA
Ig2(0): 10 14.9 mA
Gm: 9 11 mA/v
Ri: 18 15 kn
RL: 3 2 kn
Pout: 8 11 W
Dtot: 10 10 %

Driving B1 series amplify(fixuppartial voltage)
Ua: 375 400 V
Rg2: 600 800 n
Ug3: 0 0 V
-Ug1: 33 36 V
Ia(0): 2*30 2*30 mA
Ia(maxsig): 2*107.5 2*110.5 mA
Ig2(0): 2*4.7 2*4.5 mA
Ig2(maxsig): 2*23.5 2*23 mA
RL(a-a): 3.5 3.5 kn
~u(g1-g1)(r. M. S): 46.7 50 kn
Pout: 48 54 W
Dtot: 2.8 1.6 %

Rg2 is used by two tubes at the same time.
Driving B1 series amplify super line connect(auto-partial voltage)
(43% tapping points)
Ua: 430 V
Rg2: 2*1 n
Ia(0): 2*62.5 V
Ia(maxsig): 2*65 V
Ig2(0): 2*10 mA
Ig2(maxsig): 2*10.2 mA
Rk: 2*470 mA
~u(g1-g1)(r. M. S): 35 mA
RL(a-a): 6 kn
Pout: 20 W
Dtot: 0.35 %