GU47A
TETRODE
The GU47A tetrode is used as a power amplifier at frequencies up to 70 MHz
GENERAL
Cathode: directly heated, carbonized thoriated tungsten
Envelope: glasstometal with ring leads of cathode and grids
Cooling: forced (water for anode, air for stem).
Height: at most 260 mm.
Diameter: at most 91 mm.
Mass: at most 2 kg
OPERATING ENVIRONMENTAL CONDITIONS  
Vibration loads:  
frequencies, Hz  1080 
acceleration, m/s²  39 
Multiple impacts with acceleration, m/s²  118 
Ambient temperature, °C  60 to +70 
Relative humidity at +40 °C, %  9598 
BASIC DATA Electrical Parameters 

Filament voltage (AC or DC), V  6.3 
Filament current, A  5767 
Resistance of unheated cathode, Om, at most  0.01 
Grid 2 voltage, kV  0.9 
Negative grid 1 voltage (at anode voltage 1 kV, anode current 2.5 A), V  1527 
Anode current at zero grid 1 voltage (at anode voltage 1 kV, grid 2 voltage 1 kV), A, at least  3.2 
Anode current (at anode voltage 5 kV, grid 1 voltage 110 V), A, at most  0.55 
Mutual conductance (at anode voltage 1 kV, anode currents 2 and 2.5 A), mA/V  3644 
Gain coefficient (grid 2grid 1) (at anode voltage 1 kV, grid 2 voltage 2 kV, anode current 2 A)  812 
Interelectrode capacitance, pF:  
input, at most  100 
output, at most  19 
transfer, at most  0.5 
Limit Operating Values  
Filament voltage (AC or DC), V  66.6 
Filament starting current, A  90 
Anode voltage, kV  6 
Grid 2 voltage, kV  1.2 
Dissipation, W:  
anode  6x10³ 
grid 2  300 
grid 1  50 
Operating frequency, MHz  70 
Temperature at envelope, stem and glasstometal seals, °C  150 
Averaged Characteristic Curves:
U_{f} = 6.3V; U_{g2} = 0.8kV;
_____ anode;
_ _ _ gridanode;
_ . _ P_{a max}
Averaged Characteristic Curves:
U_{f} = 6.3V; U_{g2} = 0.9kV;
_____ anode;
_ _ _ gridanode;
_ . _ grid 2
Averaged Characteristic Curves:
U_{f} = 6.3V; U_{g2} = 1kV;
_____ anode;
_ _ _ gridanode;
_ . _ P_{a max}
Averaged Characteristic Curves:
U_{f} = 6.3V; U_{g2} = 1.2kV;
_____ anode;
_ _ _ gridanode;
_ . _ P_{a max}
Averaged Characteristic Curves:
U_{f} = 6.3V; U_{g2} = 0.8 kV;
_____ anode;
_ _ _ gridanode;
_ . _ grid 2 curves
Averaged Characteristic Curves:
U_{f} = 6.3V; U_{g2} = 0.9 kV;
_____ anodegrid;
_ _ _ grid 1;
_ . _ grid 2
Averaged Characteristic Curves:
U_{f} = 6.3V; U_{g2} = 1 kV;
_____ anodegrid;
_ _ _ grid 1;
_ . _ grid 2
Averaged Characteristic Curves:
U_{f} = 6.3V; U_{g2} = 1.2kV;
_____ anodegrid;
_ _ _ grid 1;
_ . _ grid 2