GU-74B

The GU-74B is a ceramic-metal forced-air cooled tetrode intended for use in amplifiers with distributed amplification and in SSB-signal amplifiers at frequencies up to 75 MHz with an output power of 2.5 kW as well as for power amplification at frequencies up to 250 MHz. in mobile radio equipment. The tube is efficiently used at low anode voltage (1 - 2 kV) with high efficiency (>50%)

Anode Dissipation .......................	2.5 kW
Screen Dissipation ......................	30 W
Grid Dissipation ..........................	1 W
Frequency for Max. Ratings ........	250 MHz
Cathode.......................................	Oxide coated
Heater Voltage ............................	27 V
Heater current .............................	3.7 A
Transconductance at Ua = 1.7 kV; Ug2 = 350 V; Ia = 1.5 A.................	65 mA/V
Capacitance Input ...................................... Output ................................... Feed-through .........................	130 pF 22 pF <0.25 pF
Max. Seal and Envelope Temperature ...............................	200° C
Maximum Length ........................	120 mm
Maximum Diameter ....................	110 mm
Weight (approximate) ................	1.8 kg
Operating Position .....................	Any
Blower ......................................	280 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	350	2.2	3	350	1.3	2.5