Palstar ZM-30, Руководство пользователя

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The ZM-30 “Digital Antenna Z Bridge” is a
quality measurement instrument that
determines antenna system performance
across the amateur bands through use of
automatically collected SWR and complex
impedance readings. It was designed to be
easily operated on the bench as well as in-
hand while portable. The analyzer is
comprised of a single printed circuit board
containing all components, connectors,
controls and a 2 row by 16 character liquid
crystal display (LCD). The enclosure holds
an 8-cell AA battery back enabling
convenient field use.
The antenna analyzer utilizes a powerful 8-
bit microcontroller to instruct a Direct
Digital Synthesis (DDS) integrated circuit to
generate RF signals from 1 MHz to 30 MHz.
The DDS generates extremely precise and
accurate signals that give the ZM-30 the
ability to also serve as a stable RF signal
source for testing and basic network
analysis. The low-current 68HC908AB32
microcontroller also handles the user
interface of an LCD, pushbuttons and rotary
encoder to allow full control of the
instrument. The “field-programmable”
feature allows the user to download new or
updated software from the ZM-30 website
and load it into the antenna analyzer.
A very low power transmitter is
automatically swept across selected
frequencies by a microcontroller. The
transmitter's signal is delivered to the
antenna system through a reflectometer
consisting of an absorptive SWR bridge
using diode detectors and compensated
buffer amplifiers. The data provided by the
reflectometer are digitized and used by the
microcontroller to compute SWR and
impedance values for each frequency
sampled. The microcontroller retains the
frequency and corresponding results
throughout the measurement period, and at
the end of the scan the microcontroller
statically displays the SWR and impedance
at the resonant frequencies.
Thus, with a press of a button the antenna
analyzer is able to quickly and automatically
determine the frequencies for which the
antenna system is best matched, and display
the associated complex impedance values at
those frequencies.
Manual operation allows the user to control
the frequency of operation while selecting
among four operational modes: Impedance,
Inductance, Capacitance and VFO.
Impedance is the most common-used mode,
useful in measuring antenna performance in
terms of SWR, Resistance and Reactance.
Inductance mode allows measurement of
inductors within the reactance range of the
instrument, as does Capacitance mode
provide for measuring capacitors. The VFO
mode allows the ZM-30 to serve as a precise
and stable frequency source, useful for
troubleshooting RF equipment or serving as
an outboard local oscillator. An audio tone
may be configured to sound relative to the
magnitude of the SWR, providing for eyes-
free operation of the instrument when
needed.