GU-43b
Tetrode

The GU-43B tetrode is used for wideband power amplification at frequencies up to 100 MHz in RF equipment. This tube is generally considered analogous to the 4CX1000.


GENERAL
Cathode:  indirectly heated, oxide-coated.
Envelope:  metal-to-glass.
Cooling:  100 m3/hour forced air.
Height, mm, at most: 125
Diameter, mm, at most: 101
Mass, Kg, at most: 1.5
GU-43b
GU-43b
C1 - grid 1; KP - cathode & heater; P - heater; C2 - grid 2; A - anode
GU-43b

ENVIRONMENTAL OPERATING CONDITIONS

Vibration loads:

frequency, Hz 10-200
acceleration, m/s² 58
Multiple impacts with acceleration, m/s² 342
Ambient Conditions:
Temperature, °C -60 to +150
Relative humidity at up to +40 °C, % 98

NOMINAL ELECTRICAL PARAMETERS
Heater voltage, V 12.6
Heater current, A 6.6
Mutual conductance (Va = 1KV, Vg2 = 300V, Ia = 600mA, change in Vg1 = 2.5V), mA/V: 45
Anode current (Ia) with Va = 3KV, Vg1 = -50V, Vg2 = 350V, A: ~0.9
Negative bias (Vg1) with Va = 1KV, Vg2 = 350V, Ia > 800mA, V: 20-30
input capacitance, pF 90
output capacitance, at most, pF 14
transfer capacitance, pF <0.1
Warm up time, s: <180
AB1 Output, Va = 3KV, Ia ~0.9A, Vg1 = -50V, Vg2 = 350V, Ig1 < 0mA, Ig2 < 80mA, KW: >1.6
Designed Tube Life (hours) >1000

ELECTRICAL PARAMETER LIMITS
Heater voltage, V 12.6 +/- ?
Heater current, A 6-7.2
input capacitance, pF 80-100
output capacitance, pF 10-18
Maximum CW Anode voltage (Va), KV: 3.3
"Maximum" Control Grid voltage (Vg1), V -200
Maximum Screen Grid voltage (Vg2), V 500
CW cathode current (Ic), A: 1
Peak cathode current (Ic), A: 3.2
Anode Dissipation, W: 1000
Screen Grid (G2) Dissipation, W: 28
Control Grid (G1) Dissipation, W: 5
Temperature at envelope (hottest point), °C 150
Frequency, MHz: <100

gu-43b
Averaged Anode Characteristic Cooling Curves:
Anode T °C plotted against Airflow, m3/sec vs Pa

gu-43b
Averaged Anode Characteristic Curves:
___ . ___ . ___  Pa Dissipation: Uf = 12.6V; Ug2 = 350V;

gu-43b
Averaged Anode Characteristic Curves:
Uf = 12.6V; Ug2 = 350V

gu-43b
Averaged Anode Characteristic Curves:
Uf = 12.6V; Ug2 = 350V