GU-74B

The GU-73B is a ceramic-metal air-cooled power tetrode intended for use as a linear SSB-signal amplifier with an output power of 2.5 kW at frequencies up to 75 MHz and as a power amplifier in wideband amplifier service at the frequencies up to 250 MHz with an output power of 1.6 kW in stationary and mobile equipments.

Anode Dissipation .......................	2.5 k W
Screen Dissipation ......................	36 W
Grid Dissipation ..........................	5 W
Frequency for Max. Ratings ........	250 MHz
Cathode.......................................	Oxide coated
Heater Voltage ............................	27 V
Heater current .............................	4.7 A
Transconductance at Ua = 1.7 kV; Ug2 = 250 V; Ia = 1.5 A.............	93 mA/V
Capacitance Input ...................................... Output ................................... Feed-through .........................	180 pF 26 pF <0.2 pF
Max. Seal and Envelope Temperature ...............................	200° C
Maximum Length ........................	150 mm
Maximum Diameter ....................	100 mm
Weight (approximate) ................	2.5 kg
Operating Position .....................	Any
Blower ......................................	150 m3/h

Class of Operation	Type of Service	Max. Ratings			Typical Operation (grid-driven)
Class of Operation	Type of Service	Anode Voltage, kV	Screen Voltage, V	Cathode Current, A	Anode Voltage, kV	Screen Voltage, V	Anode Current, A	Output Power kW
AB1	RF Linear Amplifier at 75 MHz	3.2	300	2.2	3	300	1.8	2.5
B	RF Linear Amplifier at 250 MHz	3.2	300	2.2	2.5	300	1.25	1.6