Introduction – Bird Technologies 8401 User Manual

Page 11

Chapter 1

Introduction

This publication refers to the Termaline Load Resistors

Models 8401, 8402, and 8404. The difference between

models is listed in the specifications. These models will

generally be referred to as a load throughout this man-

ual.

Purpose and

Function

These loads are portable, general purpose 50 ohm coaxial

RF transmission line terminations. They are self-

contained units requiring no outside power source or ad-

ditional equipment. They provide an accurate, dependable,

and practically nonreflective termination for testing and

adjusting RF transmitters operating in the stated fre-

quency band.

Some examples of the uses of these loads are:

As a substitute antenna.

For tuning RF transmitters - under nonradiat-

ing conditions.

For making routine tests and adjustments.

As a substitute for any 50 ohm circuit loading

element.

Description

These models are rectangular in shape with transverse

fins encasing an oil-dielectric-filled coolant cylinder. Extra

thick fins at the front and rear are bent 90° to form bot-

tom mounting flanges. These flanges are supports for free

standing use or brackets for fixed mounting. Flange holes

are provided for this purpose. A retractable handle is re-

cessed in the radiator fins.

Performance

Characteristics

and Capabilities

The loads can absorb and dissipate up to 600 W of RF

power continuously. They show a VSWR of 1.1 to 1.0

from dc to 1000 MHz, 1.2 to 1.0 from 1000-2800 MHz,

and 1.3 to 1.0 from 2800-3000 MHz.

Dimensions and

Weight

All three models have the same dimensions: 16-1/16

inches L x 5-15/16 inches W x 8-1/2 inches H (408 x 151

x 216 mm). They each have a net weight of 19.6 lb (8.9

kg) and a shipping weight of approximately 25 lb (11.34

kg).

Power and Utility

Requirements

These load resistors are passive devices that are self con-

tained and do not require a source of power or utility