**GU-61P**

**TETRODE**

The GU-61 P tetrode is used for RF power amplification at frequencies up to 70 MHz

**GENERAL**

Cathode: directly heated, carbonized thoriated tungsten

Envelope: metal-ceramic with ring leads of cathode and grids

Cooling of anode: evaporation

Height: at most 330 mm

Diameter: at most 204 mm

Mass: at most 17 kg

OPERATING ENVIRONMENTAL CONDITIONS | |

Lowest permissible ambient temperature, °C | -60 |

Relative humidity at +40 °C, % | 95-98 |

BASIC DATA Electrical Parameters |
||

Filament voltage (AC or DC), V | 6.3 | |

Filament current, A | 121-145 | |

Resistance of unheated cathode, Om | 0.005 | |

Anode current, A, at least | 5 | |

Grid 2 current (at anode voltage 2 kV, grid 2 voltage 1 kV, anode current 5 A), A, at most | 0.7 | |

Negative grid 1 cutoff voltage, (at anode voltage 10 kV, grid 2 voltage 1.5 kV, anode current 0.1 A), V, at most | 330 | |

Mutual conductance (at anode voltage 2 kV, grid 2 voltage 1.25 kV, anode currents 5 and 7 A), mA/V | 63-85 | |

Gain coefficient (grid 1-grid 2) (at anode voltage 2 kV, grid 2 voltages 1.25 and 1 kV, anode current 5 A) | 7-9 | |

Oscillatory power (at 70 MHz), kW | 30 | |

Interelectrode capacitance, pF: | ||

common-cathode circuit | common-grid circuit | |

input, at most | 320 | 150 |

output, at most | 38 | 40 |

transfer, at most | 1.4 | 0.2 |

Limit Operating Values | |

Filament voltage (AC or DC), V | 7.9-8.7 |

Filament starting current, A | 210 |

Anode voltage (DC), kV | 10 |

Grid 2 voltage (DC), kV | 1.5 |

Dissipation, kW: | |

anode | 30 |

grid 2 | 0.7 |

grid 1 | 0.3 |

Operating frequency at oscillator power output 30 kW, MHz | 70 |

Temperature at stem and ceramic-to-metal seals, °C | 175 |

**Averaged Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 500V**

**Averaged Anode Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1kV**

**Averaged Anode Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1.5kV**

**Averaged Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 500V;
_____ grid 1-anode;
_ _ _ grid 2-anode**

**Averaged Anode-Grid Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 500V**

**Averaged Anode-Grid Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1kV**

**Averaged Anode Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1.5kV**

**
Averaged Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1kV;
_____ grid 1-anode;
_ _ _ grid 2-anode
**

**
Averaged Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1.5kV;
_____ grid 1-anode;
_ _ _ grid 2-anode
**

**
Averaged Grid 1 Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 500V
**

**
Averaged Grid 1 Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1kV
**

**
Averaged Grid 1 Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1.5kV
**

**
Averaged Grid 2 Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 500V
**

**
Averaged Grid 2 Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1kV
**

**
Averaged Grid 2 Characteristic Curves:
U_{f} = 8.3V; U_{g2} = 1.5kV
**