Western electric 395 a brochure

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BELL SYSTEM PRACTICES SECTION AB46.395A
Transmission Engineering and Data Issue 2, February 1962
Electron Tube Data A. '1.& T. Co. Standard

. ELECTRON TUBE DATA SHEET
WESTERN ELECTRIC 395A ELECTRON TUBE

«I

The 395A electron tube is a ruggedized three-electrode inert-gas-filled cold
cathode tube for use primarily in triggering circuits. This tube is designed to
withstand a 1000 G centrifuge test. The 395A is also suitable for use in control
circuits such as in relay, counting or switching apparatus. Small size and pro-

. visions for wiring directly into the circuits makes this tube especially suitable
for use in small equipnent.

DESCRIPTION

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CHARACTERISTICS
. Peak Anode Voltage - . - - - - - - - - - - . - - - 140 volts
Average Cathode Current ~ - . - - - - - . . . ' . ~ 4 35 milliamperes
Average Life, Approximate - - . - - - - - - - - - - 10000 10 hours
File: 'Cold Cathode Section Indicates a change

© American Telephone and Telegraph Company, 1962 395A

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395A-PAGE 2

MAXIMUM RATINGS, Absolute System(Note U

Peak Anode Voltage (Note 2)

Forward . . . . . . . . . . . . . . . . . . . . 140 volts
Inverse . . . . . . . . . . . . . . 140 volts
-a-Forward Cathode Current (Note3)
Peak . . . . . . . . . . . . . . . . . . . . . . 35 milliamperes
Average . . . . . . . . . . . . . . . . . . . . . 13 milliamperes
Averaging Time . . . . . . . . 1 second
-->-Peak Inverse Current, Anode or Starter (Note 3).. . . . . 1 milliampere
Ambient Temperature Limits. . . . . . . . . . . . . . -55 to +85 centigrade

ELECTRICAL DATA, Throughout Life

Min. Bogey Max.

Starter Breakdown Voltage (Notes 2 & 4) . . . . . . 71 80 84 volts
Starter Voltage Drop at 10 Milliamperes . . . . . 52 65 74 volts
Anode Voltage Drop at 10 Milliamperes . . . . . . 68 80 85 volts
Transfer Current. . . . : . See Curve - Fig. 1
Required Transfer Current at 130 Anode Volts . . . 10 - - microamperes
Deionization Time, Main Gap . . . . , . . . - 2 - milliseconds
Ionization Time, Starter Gap(Note5). . . . . . . - 0.05 - millisecond

MECHANICAL DATA

Mounting Position . . . l . . . . . . . . . . . . . . . . . . . Any
Net Weight, Approximate . . . . . . . . . . . . . . . . . . . . . 0.4 ounce
Ruggedness (Note 5) . . . . . 1000 G

Dimensions and lead connections shown in outline drawing on Page 4.

I 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 by-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
L_._ location. Avoid breathing vapors from broken tubes.

Note 1: In the "Absolute System the maximum ratings specified are limiting values above which the
serviceability of the device may be impaired from the viewpoint of life and satisfactory
performance. Maximum ratings, as such, do not constitute a set of operating conditions and
all values may not, therefore, be attained simultaneously.

Note 2: Values apply with the tube exposed to light in the order of 5 to 30 foot-candles. Exposure
to direct sunlight may reduce peak anode voltage rating by as much as 45 volts and starter

breakdown voltage as much as 5 volts.
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