Bird Technologies 4308 - Manual (Page 13)

Chapter 1
Introduction
This chapter contains introductory information including product specifications, items
supplied, and accessory items.
Purpose and Function
The Model 4308 Thruline Wattmeter is a portable multi-range RF wattmeter. It is a
device which requires no external power source or batteries for operation. It is used to
measure RF power when inserted into a transmission line of 50 ohms impedance. When
operated in this manner, it is used to determine power flow and load mismatch in coaxial
transmission lines. It may be used to make measurements of CW, FM, or PM (Plane
Modulated) RF Power.
Performance Characteristics and Capabilities
On the front face of the unit, there are four power ranges which are controlled by a
selector switch. Each position of the selector switch corresponds to a power range on
the read-out meter, refer to the Specifications. There is also a “TRANSIT” position to
be used when transporting the unit. This position effectively shunts the delicate meter
movement to avoid damage from harsh blows.
The meter, line section, and related circuitry of the instrument are contained in a rugged
aluminum housing. This housing is equipped with a carrying strap, four rubber bumper
feet on the bottom, and four rubber bumper feet on the back. These bumper feet allow
the unit to be used in a standing (vertical) or flat (horizontal) position.