AOR SDU5600 Spectrum Display Unit Operating Manual

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Channel scope mode
The previous page explains the receive frequency operation in the spectrum analyser mode and step
resolution mode. The channel scope mode differs since it does not use the centre frequency (CF),
instead the receive frequency equals the marker position:
Channel Scope Mode - Receive Frequency = Receive Marker position
In addition, by use of the marker receive key MK.F you can track and select any active receive
frequency for monitoring within the frequency band presently shown on the...

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5-3 Setup of the monitoring mode
The SDU5600 is designed to provide 3 different monitoring modes such as the spectrum analyser
mode, step resolution mode and channel scope mode. Choosing the most appropriate monitoring
mode for your specific requirements is important to maximise performance and efficiency of the
SDU5600.
Method of selecting each monitoring mode:
  Spectrum analyser mode Press FUNC + 1  (SPECT)
  Step resolution mode Press FUNC + 2  (STEP)
  Channel scope mode Press FUNC + 3  (CHANL)...

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5-4  Basic setup for each monitoring mode
This section will explain how each monitoring mode has to be set up.
5-4-1  Spectrum analyser mode
Example of the screen is shown here, the
parameters are as follows:
Centre frequency (CF) =  122.5MHz
Frequency span =  10.0MHz
Start frequency =  117.5MHz
End frequency = 127.5MHz
Marker frequency =  123.5MHz
Operating step =  31.25kHz
Centre frequency (CF)
Press the CENTRE FREQ. key to make the
centre frequency display read-out appear in
reverse contrast. Enter...

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5-4-2 Step resolution mode
Example of the screen is shown here, the parameters are:
Centre frequency (CF) =  122.5MHz
Display step =  25kHz
 Frequency span =  8MHz
Start frequency =  118.5MHz
End frequency = 126.5MHz
Marker frequency =  124.35MHz
In the step resolution mode, the frequency
span is determined by the entry of display
step size, which is OPPOSITE to the
spectrum analyser mode where the
display step size is determined by the
entry of frequency span.
Centre frequency (CF)
Press the CENTRE...

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5-4-3  Channel scope mode
Example of the screen is shown here, the parameters are:
Start frequency =  118.0MHz
Step frequency =  25kHz
End frequency =  122.00MHz
Frequency span =  4MHz
Marker frequency =  121.8MHz
Receive marker =  119.7MHz
Unlike the spectrum analyser mode or step resolution
mode there is no centre frequency (CF) in the channel
scope mode.
Start frequency (Ch.START)
Press the Ch.START key to make the start frequency
read-out  display appear in reverse contrast. Enter a
desired...

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5-4-4  Common features shared by different monitoring
modes
Input sensitivity (AMPLITUDE)
This feature refers to the setup of the input
sensitivity level of the SDU5600 which is
adjusted by the internal amplifier of the
SDU5600. There are 4 different levels of input
sensitivity between 0dBm and -30dBm in 10dB
steps.
Press the AMPLITUDE special key to make the
reference level display appear in reverse contrast.
Enter the required sensitivity level via the
ten-keys or main dial, followed by ENT.
For...

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Resolution band width (RBW)
The SDU5600 provides four
selectable RBW bandwidths
which are 4kHz, 32kHz, 64kHz
and 128kHz.
Press the RBW key to make the
RBW display appear in reverse
contrast. Rotate the main dial to
select the desired value followed
by MHz or kHz to complete the
selection sequence.
The two plots here show the
results from monitoring the same
signal (80MHz WFM) but using
4kHz and 128kHz RBW
bandwidths respectively.
With the narrower RBW, the finer
signal activity can be observed.
With...

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5-5 Marker
The SDU5600 has a marker facility. The
marker is often used to obtain the reading
of the frequency of interest. In addition to
the instantaneous reading,  it provides the
peak detection and continuous peak
detection.
Press FUNC + MK.F to place the
SDU5600 in to marker mode operation.
Instantaneous readingMarker
Peak detectionPeak
Continuous peak detectionC-Peak
Instantaneous reading (Marker)
This feature is useful for many
applications. The marker can be moved
sideways by rotating the main...

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Continuous peak detection (C-Peak)
This facility is designed to continue the peak signal detection process one sweep after another.
Press the C-Peak key to activate the facility. There is no trigger level setup in the process.
To return to the instantaneous
reading either from the peak
detection mode or continuous
peak detection mode press the
CLR key... depending on the
operating configurations a multiple
press of CLR may be required.
Marker receiver (MK.F)
This facility is designed to force the...

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5-6 Calculation facility
Maximum value hold (MAX)
Press the FUNC +7 keys to activate this
facility, the legend MAX will be displayed
on the graticule section of the LCD.
Press the CLR key to exit from max hold.
Without the MAX feature being used, each
new sweep across the frequency spread
will renew the signal activities over and
over. However, with the MAX feature in
use each sweep will be retained as data is
built-up until the process ends. This is
particularly useful to detect intermittent
signals...