Bird Technologies 8251D208 - Manual (Page 13)

Chapter 1
Introduction
This publication covers the Termaline Coaxial Load Resistor
Model 8251D208. The Termaline Coaxial Load Resistor will
generally be referred to as a load thoughout this manual.
This chapter contains introductory information including
product specifications; items supplied; and accessory items
available.
Purpose and
Function
The Bird Termaline Coaxial Load Resistor is a portable,
general purpose 50 ohm coaxial transmission line termina-
tion. The load is a low reflection, nonradiating termination
for coaxial transmission lines operating in the UHF (470 -
860 MHz) band.
The load is rectangular in shape with transverse fins encas-
ing a dielectric coolant cylinder. A retractable handle is re-
cessed in the radiator fins. The front and rear fins are made
of heavier gauge material and are bent 90° to form bottom
mounting flanges. These flanges are supports for free stand-
ing use, or brackets for fixed mounting. Holes are provided
in the flanges for fixed mounting.
Applications
Use these loads:
s As a substitute antenna for tuning transmit-
ters under nonradiation conditions or making
routine test and adjustments.
s As a substitute for any circuit loading ele-
ment.
s To measure, with a suitable indication device,
the power output of any coaxially transmitted
signal within their range.
Performance
Characteristics
and
Capabilities
The Model 8251D208 load can absorb up to 1000 watts con-
tinuously and dissipate it harmlessly as heat over a fre-
quency range of 470 to 860 MHz. The actual VSWR, “voltage
standing wave ratio”, will not exceed 1.065:1 over the fre-
quency range stated.
Power and
Utility
Requirements
This load is a passive device that is self-contained and re-
quires only RF input to function.
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