Western electric 447 a brochure

Page 1

BELL SYSTEM PRACTICES SECTION AB46.447A
Transmission Engineering and Data Issue 1, June 1963
Electron Tube Data A.T.& T.Co., Standard

ELECTRON TUBE DATA SHEET
WESTERN ELECTRIC 447A ELECTRON TUBE

DESCRIPTION

The 447A is a two-electrode inert-gas filled cold cathode tube designed pri-
marily for use as a voltage reference and trouble indicator tube. The cathode red
glow is visible through a hole in the anode for indicator use.

CHARACTERISTICS

Cathode Current. . . . . . . . . . . . . . . . . . . . 8 milliamperes max.
Anode Voltage Drop . . . . . . . . . . . . . . . . 82 volts
Regulation at 2 to 4 milliamperes d-c (Note 3, page 3) . - - 0.5 volt

File: Cold Cathode Section

© American Telephone and Telegraph Company 1963

447A

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447A-PAGE2

RATINGS, Absolute System (Note n

Cathode Current, Forward

Maximum . . . . . . . . . . . . . . 8 milliamperes
Maximum Inverse Anode Current . . . . . . . . . . . . 0.0 milliampere
Ambient Temperature Limits . . . . . . . . . . . . . -55 to +60 centigrade

ELECTRICAL DATA, Throughout Life

Mia. Bogey liai-

Anode Breakdown Voltage - - 110 115 120 volts
Anode Voltage Drop(Etd)at 4 Milliamperes(D- C)(Note 2» 81 82 83 volts
Regulation (2 to 4 Milliamperes, D- C) (Note3) . . . - 0.2 0.5 volt
Coverage Current (N0te4) . . . . . . . . . . . - 3.0 4.0 milliamperes

MECHANICAL DATA

Mounting Position . . . . . . . . . . . . . . . . . . . . Any
New Weight, Approximate . . . . . . . . . . . . . . . . . 0.3 ounce
Bulb . . . . . . . . . . . . . . . . . . . . . . . . . T 6%
Base . . . . . . . . . . . . . . . . . Small Button 9 pin
Light Spot Size, approximate . . . 020 inches

Dimensions and connections shown in outline drawing on page 4.

LIFE DATA

Drift in Anode Voltage Drop (Etd) in 500 hours at 8 mAdc- - - - 0.6 volts (max.)

HANDLING

This tube contains a small amount of krypton-85 gas which is a by-product
radioactive material. The amount of krypton-85 is less than five microcuries, which
is too small an amount to require any special care in use.

Atomic Energy Commission regulations require that the individual tube carton
for tubes containing hy-product radioactive material be appropriately marked. The
marking includes the statement that tube disposal should be in approved manner.

Approved instructions for disposal of tubes containing krypton-85 are as
follows:

Tubes to be disposed of should be broken or crushed in a well
ventilated place releasing any resulting vapors to the outside
atmosphere. The residual broken or crushed tubes should be dis-
posed of in a normal public trash disposal system. Tubes should be
disposed of at a rate of not more than 100 each week from any one
location. Avoid breathing vapors from broken tubes.