Bird Technologies 8141 - Manual (Page 11)

Chapter 1
Introduction
General
This instruction book is intended for use by operators of the
Models 8141 and 8141-010 Termaline Load Resistor.
This chapter contains introductory information including
product specifications; items supplied; and accessory items.
Purpose And
Function
The Models 8141 and 8141-010 Termaline Load Resistor are
portable, general purpose 50 ohm coaxial transmission line
terminations. They are self-contained units requiring no
outside power source or additional equipment. They provide
accurate, dependable, and practically nonreflective termina-
tions for testing and adjusting transmitters under nonradi-
ating conditions from dc to 2500 MHz.
The models are rectangular in shape with transverse cool-
ing fins spaced evenly along its entire length. Their short
length makes it particularly useful in locations. Also, the
ten pounds total weight is a convenience in portable use.
Mounting holes are provided, see Chapter 3, Installation.
The RF connector, on the front face of the unit, is a Female
N similar to UG-58A/U, but is a “Quick-Change” design per-
mitting rapid and easy interchange with other AN type con-
nectors.
Performance
Characteristics
and Capabilities
The loads will absorb and dissipate as heat up to 250W of
RF power in continuous duty. It can handle up to 20 percent
overload for a maximum of ten minutes overload without
damage, provided a half-hour interval is maintained for
cooling between power applications. The design of the resis-
tor and its impedance matching shell keeps the VSWR be-
low 1.1 to 1.0 from dc to 1000 MHz, 1.2 to 1.0 from 1000 to
1800 MHz and 1.3 to 1.0 from 1800 to 2500 MHz. With its
“QC” type of connector Model 8141 can be adapted to coaxial
cables equipped with any of a variety of standard connec-
tors.
Dimensions and
Weight
Consult the Specification Sheet for the size and weight of
each load
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