AOR SDU-5500 Operating Manual

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Use the spin wheel dial to so that the required ICOM radio is highlighted then press .  The legend
“IC-R8500 Connected” (or whichever radio is specified) will briefly be displayed then the CF readout will
display the current receive frequency of the radio.  Should any fault occur in connection with the
companion radio at this stage, the SDU5500 CPU will identify the receiver as “Other” being connected.
In this case check the radio parameters (baud rate setting etc) and leads then try again.
Warm...

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Reprogramming the 10.7 MHz IF
It is possible to use a companion radio with an IF not of 10.7 MHz but within the range of 5.7 to 15.7
MHz by reprogramming the IF frequency employed by the SDU5500 to a resolution of tens of Hz.
Sweep direction is selectable depending on the heterodyne configuration of the radio, however the
maximum sweep span may be narrower than 10 MHz due to the IF characteristics and centre frequency
of the companion radio.
Usefulness
In order to provide a useful bandwidth of at...

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(5)  General operation of the SDU5500
There are effectively two methods of operation when companion radios are connected to the SDU5500:
1. Active mode, the radio is controlled from the SDU5500 in SPECTRUM, STEP
 RESOLUTION or CHANNEL SCOPE mode.
2. Passive mode, the SDU5500 does not control the radio, only the IF output is connected
between the SDU5500 and companion radio providing a bandscope of the receiver’s
passband.
5-1  Using the SDU5500... sequence to use
Connect-up the SDU5500 and companion...

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If you wish to toggle the attenuator on / off, press  ATT   This affects the gain at the receiver’s front
end and sensitivity of the companion radio.  The legend “ATT : ON / OFF” confirms attenuation setting of
the companion radio, this is not available in ‘Other’ radio operation.
If you wish to toggle the SDU5500 input gain, press  GAIN   This affects the gain of the SDU5500
and has no effect on the sensitivity of the companion radio.  The base line of the SDU5500 is equivalent
to -40dBm in HIGH and...

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The receive frequency is NOT the centre frequency of display but is equal to the START frequency, a
pair of ‘outline triangle legends’ (above and below the graphical start frequency) indicate the receive
frequency.
CHANL mode is confirmed by the legend “OP.MODE : CHANL” on the LCD.  To return to a standard
spectrum analyser display press  SPECT
Reprogramming channel scope mode:  Next time channel scope mode is used, the previous
parameters will be employed unless they are redefined using the “FREQ”...

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Each LCD-STEP will equal the total bandwidth in kHz divided by 304 dots, in the case of 10000 kHz this
would represent 10000 / 304 = 32.89 kHz.
If you wish to have one LCD-STEP to equal one tuning step of the companion radio, you must use step
resolution mode or channel scope mode.
& Note: if using step resolution mode, the menu key “SPAN” is replaced by the “STEP” key.  If the
companion radio is set to “Other”, the centre frequency is automatically set to 10.7 MHz.  Please refer to
section 4-4 of...

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& Note: If [MK-CF] is used with the companion radio set to “Other”, the IF frequency employed will be
changed from the default of 10.7 MHz.  In normal use, this should be avoided, however this may be
useful if the exact centre frequency of the companion radio is not known.
Select menu 6... analysis selection
6 PREV MAX AVR  -  - NEXT
To select  MAXIMUM trace, press  MAX    The maximum height of traces will be frozen on the display.
This will result in ‘peaks’ where transmissions have taken place, one...

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5-2  Spectrum analyser mode
The standard default mode used by the SDU5500 is spectrum analyser mode “SPECT”.
As an example of usage, monitor the FM broadcast band using spectrum analyser mode
with the AR5000.
1)  Connect the AR5000 with the SDU5500 referring
to section 4-1 of this operating manual.  First switch
on the AR5000 then the SDU5500.  Unless the
AR5000/SDU5500 combination has been previously
configured, the SDU5500 will default to “Other”
companion radio.
2)  Go to menu 1, use the  PREV...

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The default is spectrum analyser “SPECT”, if this is not already selected push  SPECT.
The LCD legend “OP.MODE : SPECT” confirms selection.
5)  Go to menu 4, if necessary use the  PREV   NEXT  keys or press the numeric key 
.  This menu
is used to input the centre frequency, define span width and sample rate.
Push the  CF  key and enter the required centre
frequency in MHz format.  In this example select 95
MHz followed by 
.  The LCD legend “CF :
95.00000MHz” confirms entry.
Push the  SPAN  key and...

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Rotate the spin wheel dial to move the marker onto
any active trace, the frequency may be read directly
in MHz format next to the legend “Marker” and the
signal level will be displayed alongside in dBm.
If the incoming signal is greater than -40dBm,
switch-on the companion radio’s attenuator (in the
case of the AR5000 this is via menu 2).
Additional facilities are provided by menu 5 and
menu 6, these include  MK-CF  where the marker
is moved to centre frequency so that activity traces
may be monitored...