BIRD 8135 Operation Manual - Purpose and Function
1
Chapter 1
Introduction
Purpose and Function
The Bird Model 8135 Termaline Load Resistor is a portable, general purpose 50
ohm coaxial transmission line termination. It is a self-contained unit requiring
no outside power source or additional equipment. This coaxial load resistor
provides an accurate, dependable, and practically non-reflective termination for
adjustment, standby, and testing of transmitters under non-radiating
conditions.
Performance Characteristics and Capabilities
The Model 8135 can absorb up to 150 watts continuously and dissipate it
harmlessly as heat over a frequency range of DC to 4000 MHz. It is designed to
show low reflectivity throughout this range. The VSWR will be 1.1 to 1.0
maximum from DC to 1000 MHz, 1.2 to 1.0 maximum from 1000 to 2500 MHz
and 1.3 to 1.0 maximum from 2000 to 4000 MHz.
Dimensions and Weight
The Model 8135 is 8-13/16 inches long, 4 inches wide, and 6-7/16 inches high
(224 x 102 x 164 mm). It has a weight of 6 lb (2.7 kg) net and a shipping weight
of 8 lb (3.6 kg).
Power and Utility Requirements
Being a passive electronic device, the Model 8135 needs no outside source or
utility service.
Environmental Requirements
The Model 8135 should be used in a dust and vibration-free environment. The
ambient temperature range should be kept between -40C and +45C (-40F and
+113F) for proper operation. Allow at least 6 inches of clearance around the
load to permit an unimpeded access of convection air currents to the load.