[Index page]   [Vacuum tubes]   [Components]   [Radio-devices]   [Assistance]   [Schematics]   [Software]   [Payment]   [Warranty]
 
 

GU-74B/4CX800A
POWER TRANSMITTING TETRODE


The GU-74B is a ceramic-metal forced-air cooled tetrode intended for use as a linear SSB-signal amplifier with output power up to 550 W at frequencies up to 75 MHz and as a power amplifier in wideband amplifier service at the frequencies up to 250 MHz. The tube can be used in stationary and mobile equipments and it is especially effective at low anode voltage     (1 - 2 kV) with high efficiency (>50%) 

CHARACTERISTICS

Anode Dissipation ....................... 600 W
Screen Dissipation ...................... 15 W
Grid Dissipation .......................... 2 W
Frequency for Max. Ratings ........ 250 MHz
Cathode....................................... Oxide coated
Heater Voltage ............................ 12.6 V
Heater current ............................. 3.6A
Transconductance at Ua = 1 kV; Ug2 = 300 V; Ia = 600 mA................. 32 mA/V

Capacitance
     Input ......................................
     Output ...................................
     Feed-through .........................


50 pF
11 pF
<0.09 pF
Max. Seal and Envelope 
Temperature ...............................
200° C
Maximum Length ........................ 90 mm
Maximum Diameter .................... 72 mm
Weight (approximate) ................ 550 g
Operating Position ..................... Any
Blower ...................................... 35 m3/h

Class of
Operation 		Type of Service Max. Ratings Typical Operation (grid-driven)
Anode
Voltage,
kV 		Screen
Voltage,
V 		Cathode
Current,
mA 		Anode
Voltage,
kV 		Screen
Voltage,
V 		Anode
Current,
mA 		Output
Power
W
AB1 RF Linear Amplifier at
75 MHz 		2.2 350 750 2 300 450 550

Intermodulation distortion of the 3rd order - minus 30 dB
 

CALCULATION OF MAXIMUM TUBE PARAMETERS
FOR CATHODE DRIVEN AMPLIFIER

_________________________________________________________________

RF LINEAR AMPLIFIER USING GU-74B TETRODE

by "RF Amplifier Developer 2001" Version 1.5
_________________________________________________________________

Plate supply voltage DC (V):................................2500

Screen supply voltage (V):..................................360

Single-tone plate current (A):..............................0.63

Zero-signal plate current (A):..............................0.05
_________________________________________________________________

Anode current conduction angle,(deg):.......................97.13

Anode current, pk.,(A):.....................................1.85

Anode current of the first harmonic, pk.,(A):...............0.953

Amplification of the valve under minimal residual voltage:..5.139

AC voltage factor of the valve anode:.......................0.856

Amplitude of RF AC voltage generated

on the valve anode,(V):.....................................2140

Minimum residual voltage of the valve anode,(V):............360

Peak voltage of the anode, max.,(V):........................4640

Maximum produced CW power on the valve anode,(W):...........1019.7

Maximum produced SSB peak power on the valve anode,(W):.....1541.8

Maximum produced SSB PEP power on the valve anode,(W):......2039.4

Factor for SSB signal, under peak-factor,(p=4):.............0.35

Average produced power of the valve anode

for SSB signal,(W):.........................................124.913

Maximum input power to the valve anode,(W):.................1575

Maximum efficiency of the valve:............................0.647

Average efficiency of the valve for SSB signal:.............0.216

Average input power to the valve anode,(W):.................578.301

Valve anode dissipation, max.,(W):..........................555.3

Average valve anode dissipation,(W):........................453.4

Anode dissipation under zero-signal plate current,(W):......125

Virtual resistance of the valve anode circuit,(ohm):........2246

_________________________________________________________________

PARAMETERS FOR THE 2 HARMONIC
_________________________________________________________________

Anode current of the 2 harmonic, pk.,(A):...................0.341

Maximum produced power for 2 harmonic,(W):..................364.87

Virtual anode resistance for 2 harmonic,(ohm):..............6276

_________________________________________________________________

PARAMETERS FOR THE 3 HARMONIC
_________________________________________________________________

Anode current of the 3 harmonic, pk.,(A):...................0.064

Maximum produced power for 3 harmonic,(W):..................68.48

Virtual anode resistance for 3 harmonic,(ohm):..............33437

 

CALCULATION OF MAXIMUM TUBE PARAMETERS
FOR GRID DRIVEN AMPLIFIER

_________________________________________________________________

RF LINEAR AMPLIFIER USING GU-74B TETRODE

by "RF Amplifier Developer 2001" Version 1.5
_________________________________________________________________

Plate supply voltage DC (V):................................2000

Screen supply voltage (V):..................................300

Single-tone plate current (A):..............................0.6

Zero-signal plate current (A):..............................0.3

_________________________________________________________________

Anode current conduction angle,(deg):.......................142.55

Anode current, pk.,(A):.....................................1.309

Anode current of the first harmonic, pk.,(A):...............0.69

Amplification of the valve under minimal residual voltege:..4.363

AC voltage factor of the valve anode:.......................0.85

Amplitude of RF AC voltage generated

on the valve anode,(V):.....................................1700

Minimum residual voltage of the valve anode,(V):............300

Peak voltage of the anode, max.,(V):........................3700

Maximum produced CW power on the valve anode,(W):...........586.5

Maximum produced SSB peak power on the valve anode,(W):.....674.5

Maximum produced SSB PEP power on the valve anode,(W):......1173

Factor for SSB signal, under peak-factor,(p=4):.............0.35

Average produced power of the valve anode

for SSB signal,(W):.........................................71.846

Maximum input power to the valve anode,(W):.................1200

Maximum efficiency of the valve:............................0.489

Average efficiency of the valve for SSB signal:.............0.111

Average input power to the valve anode,(W):.................647.261

Valve anode dissipation, max.,(W):..........................613.5

Average valve anode dissipation,(W):........................575.4

Anode dissipation under zero-signal plate current,(W):......600

Virtual resistance of the valve anode circuit,(ohm):........2464

_________________________________________________________________

PARAMETERS FOR THE 2 HARMONIC
_________________________________________________________________

Anode current of the 2 harmonic, pk.,(A):...................0.035

Maximum produced power for 2 harmonic,(W):..................29.75

Virtual anode resistance for 2 harmonic,(ohm):..............48571

_________________________________________________________________

PARAMETERS FOR THE 3 HARMONIC
_________________________________________________________________

Anode current of the 3 harmonic, pk.,(A):...................0.041

Maximum produced power for 3 harmonic,(W):..................34.85

Virtual anode resistance for 3 harmonic,(ohm):..............41463


[Back]