MaxiMuM Ratings

typical OpeRatiOn

class of

type of service

plate

plate

plate

screen

plate

Drive

Output

Operation

Voltage

current

Voltage

Voltage

current

power

power

(Volts)

(amps)

(Volts)

(Volts)

(amps)

(Watts) (kiloWatts)

c

RF amplifier

22,500

125

21,500

1,000

125

7,000

2,158.0

c

RF amplifier plate Modulated

17,500

100

17,500

1,000

95.0

6,465

1,384.0

aB1

RF linear amplifier

22,500

125

20,000

1,500

86.5

---

1,225.0

aB1

aF amplifier or Modulator

22,500

125

17,500

1,500

146

---

2,015.0

The 8974 is a power tetrode designed for very high

powered frequency or high frequency broadcast

service and very low frequency communication in

the megawatt power range. The 8974 has a two

section thoriated tungsten filament mounted on

water-cooled supports. The two sections may

be fed in quadrature to reduce hum contributed

by an arc ac power source. The maximum anode

dissipation rating is 1500 kW steady state. Large

diameter coaxial terminals are used for the control

grid and the RF filament terminals. Filament power

and filament support cooling water connections

are made through three special couplings with

threaded clamping rings.

8974 / x-2159

or contact: CPI Microwave Products Division, Eimac Operation,607 Hansen Way, Palo Alto, CA 94303

telephone

The values listed above represent specified limits for the product and are subject to change. The data should be used for basic

information only. Formal, controlled specifications may be obtained from CPI for use in equipment design.

chaRacteRistics

Plate Dissipation (Max.)

1,500 Kilowatts

Screen Dissipation (Max.)

15.0 Kilowatts

Grid Dissipation (Max.)

4.0 Kilowatts

Frequency for Max. rating (CW)

30 MHz

Amplification Factor

4.5

Filament/Cathode

Thoriated Tungsten

Voltage

16.3 Volts

Current

600 Amps

Capacitance

Grounded Cathode

Input

1600 pf

Output

250 pf

Feedthrough

6.0 pf

Capacitance

Grounded Grid

Input

675 pf

Output

260 pf

Feedthrough

1.0 pf

Cooling

Water and Forced Air

Base

Special Coaxial

Air Socket

N/A

Air Chimney

N/A

Boiler

N/A

Length

23.75 in; 60.30 cm

Diameter

17.03 in; 43.30 cm

Weight

175.0 lb; 80.0 kg