Western electric 266 b brochure

Page 1

BELL SYSTEM PRACTICES SECTION AB46.2663
TRANSMISSION ENGINEERING AND DATA ISSUE I, AUGUST I948
ELECTRON TUBE DATA A.T.&T. C0. STANDARD

RECTIFIER .
HALF-WAVE, MERCURY-VAPOR Western £196,776

DESCRIPTION

I The 2668 is a half-wave. mercury-vapor rectifier tube for use in high-voltage rectifier
circuits.

MAXIMUM RATINGS

Peak Inverse Anode Voltage 22000 volts
. Average Cathode Current (Quadrature Operation) 10 amperes

ELECTRON TUBE DATA SHEET
FILE: RECTIFIER SECTION 1
6-4" i

Page 2

266B - PAGE 2

MAXIMUM RATINGS, ABSOLUTE VAlUES
Peak Inverse Anode Voltage for

Condensed Mercury Temperature 20 to 40 C 22000 volts
Condensed Mercury Temperature 20 to 50 C , 12500 volts
Cathode Current
Peak
In-phase Operation , , 20 amperes
Quadrature Operation 40 amperes
Average
In-phase Operation . 5 amperes
Quadrature Operation 10 amperes
Surge (maximum duration 0.2 second) 200 amperes
Averaging Time 60 seconds
Frequency 150 cycles "sec.
ELECTRICAL DATA Min. Bogey Max.
Filament Voltage 4.75 5.0 5.25 volts
Filament Current at 5.0 Volts ........ 42 46 amperes
Cathode Heating Time, Required 300 ................ seconds
Anode Voltage Drop ........ 15 ........ volts
Critical Anode Voltage ................ 100 volts
MECHANICAL DATA
Net Weight, Approximate . 4% pounds
Equilibrium Condensed Mercury Temperature Rise
At Full Load, Approximate . . 18 centigrade
At No Load, Approximate . 15 centigrade
Cooling The condensed mercury temperature should be held within the range

specified for the maximum peak' inverse anode voltage appropriate to the
application. If forced-air cooling is necessary. a flow of 6 cubic feet per
minute from a 1-inch nozzle directed at the zone of mercury temperature
control just below the support collar ordinarily will be adequate.

Mounting This tube has a collar at the filament end of the tube by which it is sup-
ported when mounted. It should be mounted in a vertical position only,
with the filament end down. Connections to the anode and filament
terminals should be flexible. Sufficient clearance should be maintained
around the tube to insure free air circulation.

RATE OF CONDENSED MERCURY
TEMPERATURE RISE

31 8

KS

CONDENSED MERCURY
&

TEMPERATURE RISE, DEG. C
a)

0 IO 20 3O 40 50 60
TIME IN MINUTES