Hameg Instruments HM5012-2 Handbuch Seite 35

The numerical pad (4) is deactivated when the MARKER
function is switched on.
In ZERO SPAN mode the MARKER is automatically set to
the screen center and cannot be altered as only one
frequency is measured.
2 1 3 4
1 G H z S P EC TR U M A N A LY ZE R H M 5 01 4-
POWER
7 8 9
INT E NS
4 5 6
1 2 3
F O C U S
.
-
0 /C
TR
(7) REF.-LEVEL – Pushbutton with associated LED
Briefly depressing switches the function and the LED on.
After that the numerical pad (4) pushbutton or the TUNING
(9) knob can be used for reference level changes,
displayed on the second line of the top right readout
position (e.g. „R-34.8dBm").
The REF.-LEVEL can be set for ease of reading, shifting a
spectrum line to a suitable graticule position. The
reference level setting will not change the input
sensitivity.
If the noise band is in the lowest screen position, the
REF.-LEVEL value can only be decreased but not increased.
Additionally the noise band is shifted to the screen top,
so that the dynamic range becomes smaller.
The noise band is no longer visible when the ref. level is
in the lowest position and 5dB/div. (23) scaling is switched
on. It can be made visible again by reducing the reference
level by 40dB (e.g. from –30dBm to –70dBm).
(8) TG-LEVEL – Pushbutton with associated LED
(HM5014-2 only)
The tracking generator output level can be set by
numerical pad (4) input or TUNING (9) knob. The selected
level is displayed by the readout as the third line in top
right position (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".
(9) TUNING – Knob
The TUNING knob can be used to change all functions
with pushbuttons and associated LEDs in the upper
sector of the front panel. They are: INTENS, FOCUS, TR,
CENTER FREQ., MARKER, REF.-LEVEL and TG-LEVEL
(HM5014-2 only).
(10) 5dB/DIV. – Pushbutton with associated LED.
Briefly depressing this pushbutton switches the
vertical scale from 10dB/Div. (LED dark) to 5dB/Div.
(LED lit) and vice versa, without changing the reference
level setting.
Subject to change without notice
6
8
5 7
9
2
CENTER FREQ. T U N I N G
MHz
M A R K E R
MHz
.
REF - LEVEL
dBm
.
TG - LEVEL
dBm
.
0 1 5 M H z - 10 5 0 M H z
With 5dB/Div. selected, the display range is 40dB instead
of 80dB.
Note:
S w i t c h i n g o v e r t o 5 d B / D i v. c a n c a u s e t h e
noise band to „disappear" from the screen,
but it can be made visible again by changing
the REF.-LEVEL (7).
ZERO SPAN A B A AVERAGE
SAVE B M a x
SET
A - B
SPAN RECALL LOCAL/PRINT
SET R M
24 22 19
20 17
21 18
23
(11) ATTN. – Pushbuttons with associated LEDs
Briefly depressing one of the pushbuttons switches the
attenuator in 10dB steps from 0dB to 40dB resp. from
40dB to 10dB.
The measuring range depends on the input attenuator
setting. If 10dB/div. is set (80dB scale), the following
measuring ranges are available:
Attenuator setting Reference Level
40dB +10dBm
30dB
20dB 10dBm
10dB 20dBm
Pressing and holding the upper pushbutton causes switch
over from 10dB to 0dB. Due to the high sensitivity of the
input stage, this measure has been taken to protect the
input stage from being set to 0dB inadvertently.
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.
The measuring range at 0dB attenuator setting is from –
30dBm (REF.-LEVEL) to approx. –100dBm (noise level).
(12) 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 filter is displayed when a signal passes the IF
filter causing the beam to be deflected 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 identified 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.
Controls and readout
5dB/DIV
VBW
kHz
4
. H L D
dB
kHz
0
1000 10
RBW 20 AT TE N
120
9 30
40
14 12 13
16
15
approx. Noise Level
-60dBm
0dBm -70dBm
-80dBm
-90dBm
.
0 dB
.
10
11
35