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4.0 Operation
1) Power Control
The ZM-30 utilizes a unique power circuit that is controlled by the momentary contact On/Off pushbutton
located on the front panel. Power is turned on to the unit by pressing-and-holding the On/Off pushbutton until the
version of software is displayed, and then the pushbutton can be released. Turning off the ZM-30 is equally simple;
just press-and-hold the On/Off pushbutton until “Stopped” is displayed on the LCD.
Powering on the ZM-30
Upon applying power, the unit will sequence through two LCD displays before automatically entering the
Impedance mode display.
a)
Press-and-Hold the On/Off pushbutton --
The first information that appears on the LCD indicates the
approximate battery (or supply) voltage, and it is displayed for about ½ second. This is a useful feature
that indicates the relative state of the instrument’s power source.
Battery: 9.04V
The next information that is automatically displayed is the version number of the software loaded in the
instrument:
ZM-30 v2.2
c) Release the On/Off pushbutton –
Upon release of the On/Off pushbutton, the instrument enters the
Impedance mode, which is the most common use of the analyzer, indicating a screen such as that shown
below. The initial frequency that is generated and displayed is 10.00000 MHz; and with no antenna or
load connected to the RF output jack, the open circuit SWR and impedance will likely indicate as shown
below. (See “Impedance Mode” for detailed description of this display and mode operation.)
SWR 10,000.00
>10 Z>600
2) User Interface
The user interface consists of four pushbuttons, one for each instrument function as described in the next section,
and a rotary dial that is used to select various options presented in a menu-like manner. You use the function
pushbuttons and the dial to operate the ZM-30 – just press a function button and rotate the dial and the various menu
options for that function are sequentially displayed on the LCD. Once you have dialed up the desired option or
operation on the LCD, you may select it by pressing the dial pushbutton.
3) Function Selection
At any time during the instrument’s operation, you have the option of pressing any of the funtion pushbuttons to
perform the corresponding operation, as described below.
a)
BAND
-- Pressing BAND pushbutton will present four band options: 1-10 MHz, 10-20 MHz, 20-30 MHz,
and “Custom Band”. (The Custom Band is a user-specified start/stop frequency pair, set under the
Configuration function, that allows the user to specify a custom frequency range for scanning.) Once you
have dialed in the range that you wish to automatically scan, press the dial pushbutton to select it. You will
then exit back to the Impedance display.
b)
SCAN
-- Pressing the SCAN pushbutton will automatically sweep the antenna analyzer test signal across
the band range previously selected, incrementing from the lower frequency limit to the upper frequency
limit, in steps of 100 Hz, 1 kHz, 10 kHz, or 100 kHz, as preset in the Config menu. The red BUSY LED is
turned on during the scan and the following message is displayed:
~~Scanning~~
(please wait)
The reflectometer signals are sampled after each step change and are used to compute the SWR and
complex impedance at each frequency step. Each SWR value is compared to previous value in order to