BX-245 • 9
© Box 73 Amateurfunkservice GmbH 2019
Although the FA-VA5 has a relatively
large range of functions, the operation is
quite intuitive. Therefore, the following
guide has the character of a reference
book. However, the general operating in-
structions in the previous section should
always be observed. The instrument can-
not be destroyed by pressing buttons the
wrong way, and at worst this will provide
unexpected or erroneous measurement re-
sults. Therefore, it is recommended that
less experienced users start-off by measur-
ing some components with known values,
then gradually explore the operation of the
antenna analyzer by trying out different
measurement and display modes. If ambi-
guity arises please consult this manual.
For precise measurements, calibration
(
SOL compensation
) is important. It is
therefore detailed in this independent sec-
tion of the functional description. The an-
tenna analyzer works according to the fol-
lowing principle: An internal oscillator
generates a signal with a specified fre-
quency, which is routed via the BNC out-
put socket of the device to a test object (for
example an antenna). Due to the electrical
properties of the test object, the test signal
is changed in amplitude and phase. This
change is measured to determine the
impedance relative to known component
values either directly or through the reflec-
tion coefficient (after calibration has been
performed). All other values(e.g. SWR)
are mathematically calculated from the
measured impedance by the built-in mi-
crocontroller.
n
Controls and Connectors
The only measurement port on the analy-
zer is the BNC connector.
For operation, an on / off power switch
and three press buttons are available. The
Analyzer will always be in the previous
measurement mode after power is
switched on as all parameters are saved
when power is switched off. The three but-
tons have different functions depending on
the selected measuring or operating mode.
In general, a function is called up or a se-
lection is made with the left push button.
The centre and right buttons are used to
reduce or increase numerical values or to
move through menu lists.
A rapid change of numerical values (e.g.
frequency values for multi-frequency
measurements) can alternatively be ob-
tained by pressing and holding the middle
or right buttons. At any time, the available
functions are displayed on the display
above each of the buttons.
A 2-second long press on the left button
calls up the menu mode in measuring
mode. After that, the middle and right but-
tons allow you to select a menu item
which can then be selected or activated
with the left button. Other button functions
are explained in the following sections.
This description refers to the firmware
version 1.09.
Directions for use
