The WATERS Model 369A REFLECTOMETER Is a dual Indicator
voltage standing wave ratio measuring instrument for use
with high frequency radio transmitters (3.5 - 30 MHz) to
measure and indicate the impedance match between the RF
transmission line and the antenna. Since the Model 369A
REFLECTOMETER is equipped with a dual indicating meter, both
the Forward and Reflected Power readings are displayed
simultaneously. The power scales are directly calibrated in
RF watts (at 50 ohms impedance), thus the REFLECTOMETER, in
conjunction with a good 50 ohm Dummy Load, is also an
accurate RF Wattmeter.
In most applications of VSWR measurements, the user is
primarily interested in readings approaching a 1:1 ratio.
The Model 369A REFLECTOMETER, unlike most other equipments,
provides a multiple choice of power scales which, in effect,
increase the Reflected Power reading sensitivity by 10
times, thus permitting accurate determination of VSWR as low
as 1.1:1. Single scale VSWR instruments simply cannot
approach this low value with significant accuracy.
The Model 369A REFLECTOMETER consists of two separate units,
connected by a five conductor cable. The Indicator contains
a dual movement power meter and range selector. The
Directional Coupler is designed to be mounted remotely as
the transmitter RF output terminal in series with a 50 ohm
coaxial transmission line. Terminals on the Directional
Coupler are BNC type (UG-1094/U), and two BNC to UHF
adapters are furnished to permit use with the popular PL-259
connectors. For use with other types of connectors, standard
in-line adapters are available commercially. No external
power is required to operate the REFLECTOMETER, and its
insertion loss is negligible.