Hameg HM5014-2 Manual page 30

C o n t r o l s a n d r e a d o u t
is displayed by the read-out as the third line in top right posi-
tion (e.g. txxxdBm or TxxxdBm). The small letter "t" indicates
that the TRACKING GENERATOR OUTPUT is switched off. The
ON-condition is indicated by the capital letter "T".
TUNING
The knob TUNING can be used to change all functions with pushbut-
tons and associated LEDs in the upper sector of the front panel. They
are: INTENS, FOCUS, TR, CENTER FREQ., MARKER, REF.-LEVEL
and TG-LEVEL.
5 dB/DIV.
Pushbutton with associated LED
Pressing this pushbutton switches the vertical scale from 10 dB/Div.
(LED dark) to 5 dB/Div. (LED lit) and vice versa, without changing the
reference level setting. With 5 dB/Div. selected, the display range is
40 dB instead of 80 dB.
Note:
Switching over to 5 dB/Div. can cause the noise band to "disappear"
from the screen, but it can be made visible again by changing the
REF.-LEVEL .
ATTN.
Pushbuttons with associated LEDs
Pressing one of the pushbuttons switches the attenuator in 10 dB steps
from 0 dB to 40 dB resp. from 40 dB to 10 dB. The measuring range
depends on the attenuator setting. If 10dB/div. is set (80dB scale), the
following measuring ranges are available:
Attenuator setting Reference Level
40 dB +10 dBm
30 dB
20 dB 10 dBm
10 dB 20 dBm
Pressing and holding the upper pushbutton causes switch over from
10 dB to 0 dB. Due to the high sensitivity of the input stage, this measu-
30
Subject to change without notice
approx. Noise Level
–60 dBm
0 dBm –70 dBm
–80 dBm
-90 dBm
re has been taken to protect the input stage from being set to 0 dB
inadvertently.
IMPORTANT:
It must be emphasized once again that the maximum permissible
input voltages must not be exceeded. This is of high importance
as the analyzer may only display a part of the spectrum and high
signal levels outside the measuring range may cause measuring
errors or in worst case destruction of the input section.
RBW
Pushbuttons with associated LEDs
The pushbuttons allow you to select one of three IF bandwidths. A lit
LED indicates the actual bandwidth setting.
With the exception of ZERO SPAN, the curve of the selected IF fi lter
is displayed when a signal passes the IF fi lter causing the beam to
be defl ected to the screen top, depending on the signal strength. It
depends on the IF bandwidth (RBW=Resolution Bandwidth) whether
two different sine wave signals with minor frequency distance can be
displayed separately. For example, two sine wave signals with 40 kHz
signal difference and equal amplitude can be identifi ed as two different
signals if 9 kHz RBW is selected. With 120 kHz or 1 MHz RBW selected,
the two signals are displayed as one signal only.
A smaller IF bandwidth shows more details, but has the disadvantage
that the building up time is higher. If due to high SPAN setting there is
not enough time for building up, the spectrum analyzer automatically
increases the time for a SPAN. This becomes visible by a reduced
measurement repetition rate.
If the lowest repetition rate is still not suitable for correct measurement,
the readout displays „uncal", as under such circumstances the signal is
displayed with too low a level. For proper measurement the SPAN must
then be reduced until the „uncal" information is no longer displayed.
For the ease of operation it is advisable to set the signal to the center
before reducing the SPAN.
With the 4 kHz video fi lter activated, the bandwidth reduces once again.
A smaller bandwidth reduces the noise and offers a higher sensitivity.
This becomes evident when switching from 1000 kHz to 9 kHz RBW.