Bird Technologies 4331 - Manual (Page 15)

Chapter 1
Introduction
Purpose and Function
This instruction book covers the use and operation of the basic Model 43
Thruline Wattmeter. These instructions also apply to other units that are
very similar to the Model 43 in electrical characteristics and operation.
These different models and their variations (refer to About This Manual for
a complete listing) are also included in this book; however, the operational
procedures and, in most cases, the electrical specifications of the Model 43
apply to these units as well. The basic difference in the majority of these
units is physical, being panel rack mounted versions of the Model 43 Thruline
Wattmeter. However, two of the units are similar in appearance but differ
in as much as they have an RF sampler port included. The Model 43P has
peak power handling capabilities.
All differences pertinent to these units can be found in the specifications for
each of these models, in the back of this book.
The Model 43 Thruline Wattmeter is an insertion-type RF wattmeter, de-
signed to measure power flow and load match in 50 ohm coaxial transmission
lines. It is intended for use on CW, AM, FM, and TV modulation envelopes,
but not pulsed modes. The Model 43, when used in 50 ohm applications, has
an insertion VSWR of less than 1.05 to 1, up to a frequency of 1000 MHz.
The meter is direct reading in watts, expanded down scale for easy reading
and is graduated 25, 50, and 100 watts full scale. The power ranges used
are determined by the Plug-In Elements, which fall in various power and
frequency ranges (refer to the Bird Electronic Corporation Catalog).
Performance Characteristics and Capabilities
The Model 43 Thruline Wattmeter is a portable unit contained in a die cast
aluminum housing, with a formed metal enclosure on the back which is easily
removed. Included with the unit is a carrying strap, four rubber bumpers on
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