BIRD TERMALINE 8135, Инструкция

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Chapter 2
Theory of Operation
General
The Model 8135 TERMALINE Load consists essentially of a
cylindrical film type resistor immersed in dielectric coolant.
The resistor, individually selected for its accuracy, is en-
closed in a special tapered housing which provides a linear
reduction in surge impedance directly proportional to the
distance along the load resistor. This produces the uniform,
practically reflectionless line termination over the stated
frequencies of the load.
Dielectric
Coolant and
Seal
The coolant oil is chosen for its desirable dielectric proper-
ties and thermal characteristics. Cooling of the load is ac-
complished by natural fluid and air convection. The
dielectric coolant, 0.1 gallon, carries the electrically gener-
ated heat from the resistor to the walls of the cylindrical
cooling tank.
The tank is encased in a set of heavy gauge metal radiating
fins, which are firmly pressed on the cylinder. The heat
from the oil is transferred to the surrounding air by the ra-
diating fins.
A synthetic rubber diaphragm located in the rear dome of
the load allows the coolant to expand as the temperature
rises.
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