BX-245 • 15
© Box 73 Amateurfunkservice GmbH 2019
Multifrequency measurements
The
Multi Frequency Modes
menu item
allows the SWR to be measured on five
frequency bands. There is also a Sweep
mode to measure SWR, impedance Z and
reflection coefficient S (multi-frequency
measurement). The Sweep mode can be
selected as a single or cyclic run.
SWR measurement on five
frequencies
In
SWR 5 Band
mode (Fig. 23), five SWR
values are displayed in the bar graph for
five different frequencies.
The actual five frequencies can be entered
or changed in the Setup mode via menu
item 5 Band Frequencies. Fig. 25 shows
an example of setting the frequency
ƒ
1
. It
is analogous to setting the measuring fre-
quency of the Analyzer in Single Frequen-
cy Mode. Then press the
button re-
peatedly until the abbreviation
is
shown to the right of the frequency value.
After pressing the
or
button, you
can move to
ƒ
2
,
ƒ
3
etc. (see also section
Setup). There is no further operating op-
tion in this measuring mode. With this
measurement mode, you can check and
capture the effects of changes made to
multiband antennas in one simple mea-
surement. In addition to the use of master
calibration, current calibration via the
menu item
SOL 5 Band
is also possible
for this mode (Fig. 24). Prior to perform-
ing Current calibration, however, the five
required measuring frequencies must have
been selected first.
Sweep mode
The Sweep mode (multi-frequency mea-
surement) has three different sub-modes,
which are selected via the left button and
marked with an icon in the upper left cor-
ner of the display. The three sub-modes are
indicated with characters
<
,
>
and
M
Mode 1:
this mode is indicated by charac-
ter
<
and provides changing of the centre
frequency. The SWR is displayed above
the frequency. In addition, a small rectan-
gle on the SWR curve indicates the posi-
tion of the marker (see sub-mode
M
). The
centre vertical line corresponds to the in-
dicated centre frequency (7300 kHz in
Fig. 26). The full frequency range extends
to the left and right according to the se-
lected frequency range (here ± 2000 kHz).
The middle and right buttons can be used
to reduce or increase the centre frequency
by 100 kHz. At the same time, a new mea-
suring cycle over the specified frequency
range is initiated each time the button is
pressed.
Fig. 24: Additional current calibration option
for the mode
SWR 5 frequencies
Fig. 23: Simultaneous SWR measurements
on 5 programmable frequencies
Fig. 25: Selection of frequency
f
1
