Western electric 308 b brochure

Page 1

3083

Western Electric
3083 Vacuum Tube

Classlflcntlon-Fllamentnry air-cooled trlode

This tube was designed primarily for use as an audio-frequency amplifier or modulator; Dl' as
n radio-frequency oscillator or amplifier.

Blmenslonk-Dimensions and outline diagrams are shown in Figures 1 and 2 and are:
13%
3%

Maximum overall length .......
Maximum diameter ..............

Copyrlght 1933 Wuurn Emu-i: Company, incorporated

Page 2

3083

Mounting-Large four-pin bayonet base for use in a \V. E. 113A or similar socket, for either
vertical or horizontal mounting. If mounted horizontally the plane of the filament, which is
indicated in Figure 2, should be vertical.

Fllnmenh-Thoriated tungsten.

Filament voltage ...................................... 14 volts
Nominal filament current ..... 6 ampercs
Average thermionic emission .............. 4 amperes

Approximate Direct Intercleetrode Capacitancos

Plate to grid. .............
Grid to filament.
Plate to filament ..........

CharaChristies-Performance data given below are based upon a typical set of conditions.
Variations can be expected with different circuits and tubes.

Figures 3 and 4 give the static characteristics of a typical tube plotted against grid and plate
voltages.

Average Characteristlcs at 1500 volts direct plate potential and minus 150 volts grid bias,
1. == .167 ampere.

Amplification factor. . . . . . . . . . .
Plate resistance... . . . . . . . . ..
Grid to plate trantonductnnce..

1070 ohms
7500 micremhos

Operation
Maximum Rntlngs

Max. direct plate voltage. . .. ... . . . . . . . .. . 2250 volts
Max. direct plate current. 326 milliamperes
Max. plate dissipation. . . 250 watts
Max. direct grid current 75 milliamperes
Max. r-l' grid current. . . . 5 emperes
Max. frequency {or the above ratings. . . 1.5 megacytles
Max. plate voltage for upper frequency limit of 4.5 Me. 760 volts

Max. plate voltage for frequencies between 1.5 and 4.5 M: In proportion.

The above are maximum ratings which do not apply simultaneously hut depend on the
type of service as specified below.

Class A Audlo Amplifier 01- Modulator

Direct plate voltage 1500 1000 volts
Grid bias ......... -155 -80 volts
Direct plate current 135 210 milliamperes
Plate dissipation. . 200 210 watts
Load impedance. . 13000 3000 ohms
Undistorted output ...... 50 85 watts