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2.7GHz Spectrum Analyzer Service Manual
GSP-827
2.7GHz Spectrum Analyzer
Service Manual
I S O - 9 0 0 1 CE R T I F I E D M A N U FA C T U R E R
1
2.7GHz Spectrum Analyzer Service Manual
Rev. No. Revised Approved Date Description
1.0 YJ Liao 22 SEP, 2003 Preliminary Version
1.1 YJ Liao 02 DEC, 2003 Formally Released
Signature Date Document Title
Author YJ Liao 02 DEC, 2003 GSP827 Service Manual
Check
Approval
Goodwill Instrument Co., LTD.
No. 95-11, BAO-CHUNG
ROAD,
HSIN-TIEN CITY, TAIPEI
HSIEN,
TAIWAN
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2.7GHz Spectrum Analyzer Service Manual
Table of Contents Pages
1.0 GENERAL ............................................................................................................................................8
1.1 FLOW CHART OF USING THIS MANUAL ...............................................................................................9
2.0 SPECIFICATIONS............................................................................................................................10
3.0 SPECIFICATION VERIFICATION ...............................................................................................13
3.1 FREQUENCY ACCURACY- CENTER AND SPAN. .................................................................................14
3.2 RBW ACCURACY .............................................................................................................................15
3.3 AMPLITUDE ACCURACY ...................................................................................................................17
3.4 REFERENCE LEVEL ATTENUATION ERROR .......................................................................................18
3.5 AMPLITUDE LEVEL LINEARITY .........................................................................................................19
3.6 FREQUENCY FLATNESS ....................................................................................................................20
3.7 TG OUTPUT ACCURACY (OPTIONAL) ...............................................................................................21
3.8 TG ATTENUATION ACCURACY OF OUTPUT (OPTIONAL) ..................................................................22
3.9 TG OUTPUT FLATNESS (OPTIONAL) .................................................................................................23
3.11 RECORDING TABLES.......................................................................................................................24
TABLE 3.1 FREQUENCY ACCURACY-CENTER AND SPAN ........................................................................24
TABLE 3.2 RBW BANDWIDTH ...............................................................................................................24
TABLE 3.3 AMPLITUDE ACCURACY TEST ................................................................................................24
TABLE 3.4 REFERENCE LEVEL ATTENUATION ACCURACY ....................................................................24
TABLE 3.5 AMPLITUDE LEVEL LINEARITY .............................................................................................25
TABLE 3.6 FREQUENCY FLATNESS TEST ................................................................................................26
TABLE 3.7 TG OUTPUT ACCURACY TEST (OPTIONAL)...........................................................................27
TABLE 3.8 TG ATTENUATION ACCURACY TEST (OPTIONAL).................................................................27
TABLE 3.9 TG OUTPUT FLATNESS TEST (OPTIONAL) .............................................................................27
4.0 OPERATION THEORY ...................................................................................................................28
4.1 GENERAL DESCRIPTION ...................................................................................................................28
4.2 RF MODULE .....................................................................................................................................28
4.3 LO2 MODULE ...................................................................................................................................28
4.4 IF MODULE .......................................................................................................................................29
4.5 DSP MODULE ...................................................................................................................................29
4.6 MOTHER BOARD ...............................................................................................................................30
4.7 TG (OPTION) ....................................................................................................................................30
4.8 POWER SUPPLY MODULE (STANDARD)..............................................................................................30
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2.7GHz Spectrum Analyzer Service Manual
4.9 DC/AC/BATTERY OPERATIONAL POWER SUPPLY (OPTION)..............................................................30
4.10 HIGHER STABILITY TIME BASE (OPTION).........................................................................................30
5.0 TROUBLE SHOOTING GUIDE......................................................................................................31
5.1 SYSTEM DIAGNOSIS .........................................................................................................................31
5.1.1 Diagnosis information .............................................................................................................31
5.1.2 LO1 Unlocked..........................................................................................................................32
5.1.3 LO3 Unlocked..........................................................................................................................32
5.1.4 Reference Unlocked. ................................................................................................................32
5.1.5 External Reference Unlocked ..................................................................................................32
5.2 NO DISPLAY WHEN POWER UP .........................................................................................................32
5.3 NO SIGNAL ON DISPLAY ...................................................................................................................33
5.4 FAIL TO MEET SPECIFICATION ..........................................................................................................33
5.5 TROUBLESHOOTING MAP .................................................................................................................34
5.6 SPARE PART LIST .............................................................................................................................36
6.0 UNIT CALIBRATION ......................................................................................................................37
6.0.1 GENERAL DESCRIPTION.................................................................................................................37
6.0.2 CALIBRATION EQUIPMENT REQUIRED ............................................................................................38
6.1 CALIBRATION START ........................................................................................................................39
6.1.1 Enter Calibration mode ...........................................................................................................39
6.2 IF FINE GAIN SETTING......................................................................................................................40
6.3 FREQUENCY RESPONSE CALIBRATION .............................................................................................42
6.3.1 Set 3k RBW offset to 0..............................................................................................................42
6.3.2 Frequency Response Calibration.............................................................................................43
6.3.2.1 Setup .....................................................................................................................................43
6.3.2.2 Calibration Procedures ........................................................................................................43
6.4 RBW OFFSET CALIBRATION ............................................................................................................49
6.5 LO1 GAIN CALIBRATION .................................................................................................................51
6.6 TG (OPTION) CALIBRATION ..............................................................................................................53
6.6.1 Setup ........................................................................................................................................53
6.6.2 TG: Frequency calibration ......................................................................................................53
6.6.3 TG: Fine level calibration .......................................................................................................57
6.7 INTERNAL CALIBRATION SIGNAL LEVEL ...........................................................................................58
6.8 MAKING BACK UP OF CALIBRATION DATA ........................................................................................59
6.8.1 Recording calibration data by tool ..........................................................................................59
6.8.2 Recording calibration data manually ......................................................................................62
6.9 SENDING CALIBRATION DATA TO UNIT .............................................................................................70
7.0 ASSEMBLY/DISASSEMBLY OF UNIT.........................................................................................71
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2.7GHz Spectrum Analyzer Service Manual
7.1 EXPLOSION DIAGRAM .......................................................................................................................72
7.2 REMOVING THE CASE .......................................................................................................................73
7.2.1 Removing belt and rear frame .................................................................................................73
7.2.2 Removing outer case................................................................................................................74
7.3 CABLE ASSEMBLY AND WIRE CONNECTORS ......................................................................................75
7.4 POWER SUPPLY MODULE ASSEMBLY .................................................................................................76
7.4.1 DC/DC Module (option) ..........................................................................................................77
7.4.2 AC/DC Module ........................................................................................................................78
7.5 RF MODULE ASSEMBLY ....................................................................................................................79
7.6 LO2 MODULE ASSEMBLY .................................................................................................................80
7.7 IF MODULE ASSEMBLY .....................................................................................................................81
7.8 DSP MODULE AND GBIP MODULE (OPTIONAL) ASSEMBLY .............................................................82
7.9 TG (OPTION) MODULE ASSEMBLY ....................................................................................................83
7.10 1PPM TIME BASE (OPTION) ASSEMBLY ............................................................................................84
7.11 MOTHER BOARD AND CHASSIS .......................................................................................................85
7.12 FRONT FRAME, KEYBOARD AND DISPLAY .......................................................................................86
8.0 BOARD LEVEL ADJUSTMENTS ..................................................................................................86
8.1 GENERAL DESCRIPTION ...................................................................................................................87
8.1.1 Flow chart of Manufacture Adjustments..................................................................................87
8.1.2 Removing and Installing Module Shields.................................................................................88
8.1.3 Adjustment equipments required..............................................................................................88
8.1.4 Rear Panel Adjustments...........................................................................................................88
8.2 BOARD ADJUSTMENTS .....................................................................................................................89
8.2.1 RF MODULE ..................................................................................................................................89
8.2.1.1 452MHz filter adjustment .....................................................................................................89
8.2.1.2 LO1 PLL adjustment.............................................................................................................90
8.2.1.3 Shield assembly.....................................................................................................................90
8.2.2 LO2 Module .............................................................................................................................91
8.2.3 IF Module ................................................................................................................................92
8.2.4 DSP, Mother board and Power Modules.................................................................................94
8.3 TG ADJUSTMENTS ...........................................................................................................................95
8.4 UNIT CALIBRATIONS ........................................................................................................................96
9.0 OPTION INSTALLATION...............................................................................................................97
9.1 TG MODULE .....................................................................................................................................97
9.1.1 Record the level readings of Cal signal ...................................................................................97
9.1.2 Install the TG module ..............................................................................................................97
9.1.3 Update the calibration data .....................................................................................................97
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2.7GHz Spectrum Analyzer Service Manual
9.1.4 Enable TG Function.................................................................................................................99
9.1.5 Check level readings of Cal signal ..........................................................................................99
9.2 DC/AC/BATTERY OPERATIONAL POWER........................................................................................100
9.3 1PPM TIME BASE MODULE ...............................................................................................................101
9.4 GPIB MODULE ...............................................................................................................................102
10.0 PART LIST.....................................................................................................................................103
10.1 RF MODULE .................................................................................................................................103
10.1.1 PCB part placement.............................................................................................................103
10.1.2 RF module part list ..............................................................................................................104
10.2 LO2 MODULE ...............................................................................................................................106
10.2.1 LO2 PCB part placement.....................................................................................................106
10.2.2 LO2 module part list ............................................................................................................107
10.3 IF MODULE ...................................................................................................................................108
10.3.1 IF PCB part placement ........................................................................................................108
10.3.2 IF module part list ...............................................................................................................109
10.4 DSP MODULE ...............................................................................................................................113
10.4.1 DSP PCB part placement ....................................................................................................113
10.4.2 DSP PCB part list ................................................................................................................114
10.5 MOTHER BOARD AND KEYPAD .....................................................................................................116
10.5.1 MB/Keypad PCB part placement.........................................................................................116
10.5.2 MB/Keypad part list.............................................................................................................117
10.6 TG (OPTION) ................................................................................................................................118
10.6.1 TG part PCB placement.......................................................................................................118
10.6.2 TG module part list ..............................................................................................................119
10.7 DC/DC MODULE (OPTION) ...........................................................................................................122
10.7.1 DC/DC PCB part placement................................................................................................122
10.7.2 DC/DC module part list.......................................................................................................123
10.8 GBIP (OPTION) PCB PART PLACEMENT .......................................................................................124
10.8.1 GBIP PCB part placement...................................................................................................124
10.8.2 GBIP part list.......................................................................................................................124
10.9 1PPM STABILITY TIME BASE (OPTION) PCB PART PLACEMENT ....................................................125
10.9.1 1ppm Time Base PCB part placement .................................................................................125
10.9.2 1ppm Time Base part list .....................................................................................................125
10.10 PACKING ASSEMBLY PART LIST .................................................................................................126
10.11 MECHANICAL PART LIST ............................................................................................................127
11.0 SCHEMATICS ...............................................................................................................................128
11.1 RF MODULE .................................................................................................................................128
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2.7GHz Spectrum Analyzer Service Manual
11.2 LO2 MODULE ...............................................................................................................................132
11.3 IF MODULE ...................................................................................................................................134
11.4 DSP MODULE ...............................................................................................................................142
11.5 MOTHER BOARD/ KEYPAD ...........................................................................................................143
11.6 TG MODULE .................................................................................................................................146
11.7 DC/DC MODULE ..........................................................................................................................153
11.8 GPIB MODULE .............................................................................................................................155
11.9 1PPM TIME BASE ..........................................................................................................................156
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2.7GHz Spectrum Analyzer Service Manual
1.0 General
The purpose of this document is to provide the necessary information for service
features. The contents and timing of usages are as follows.
Chapter 2 is specifications. Which lists the complete specifications including all
options.
Chapter 3 is the procedure of specification verification. Specification verification is
performed in the situation like IQC (incoming quality control) of this unit, performance
verification of regular plan and after trouble fixing.
Chapter 4 is operation theory of this unit. This is a preparation for the next coming
chapters. Basic circuitry descriptions and block diagrams are described.
Chapter 5 is trouble-shooting guide. In this chapter, we start form system diagnosis
that gives information of self-diagnosis on display. And then a diagnosis map is given to
help developing a strategy for trouble-shooting. A spare part list is attached as the end of
this chapter.
Chapter 6 introduces the calibration procedure that is implemented by the front panel
operation. This calibration is the most useful for making performance agreed in many
cases. The procedure of using PC tool to access calibration data is also presented.
If calibration by panel operation does not work out for the specification agreement,
opening the case to swap the fault module or tune the system could be necessary.
Chapter 7 gives the information of assembling and disassembling this unit. The
explosion diagrams and procedures of separate modules are described.
Chapter 8 gives the detailed information of adjustment on board level. It is used at
the timing when the front panel calibration cannot cover performance agreement.
Chapter 9 is the information of option installation in spite of the installation in user
side is not encouraged. Chapter 10 and 11 are the part list and schematics.
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2.7GHz Spectrum Analyzer Service Manual
1.1 Flow Chart of using this manual
The flow charts of how to use this manual under different situations are as follows.
Regular specification verification
Check specification Verify specification
(Ch2) (Ch3)
Option installation
Calibrate again and
Open the unit case. Install the options.
verify specification.
(Ch7) (Ch 9)
(Ch6, Ch3)
Trouble shooting
Study theory. Diagnose the system.
(Ch4) (Ch5)
Calibrate again and
verify specifications.
(Ch6, Ch3)
if not done
Perform board level adjustment, calibration and then
verify specifications.
(Ch7, Ch8, Ch6, Ch3)
if not done
Perform the board swapping if a spare module exists.
(Ch7, Ch6, Ch3)
if not done
Refer to circuitry schematics to fix the board. Perform
board level adjustment, calibration and then verify
specifications.
(Ch11, Ch8, Ch6, Ch3)
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2.7GHz Spectrum Analyzer Service Manual
2.0 Specifications
Specifications are subject to change without notice. Refer to Goodwill Instrument
Co., LTD. for latest specifications.
Item Specification
Frequency Range 9kHz-2.7GHz
Accuracy see time base
Span Accuracy see time base
Span Range 2kHz to 2.5GHz in 1/2/5 sequence, full span,
zero span
Phase Noise -85dBc/Hz typical @ 1GHz 20kHz Offset
Time Base ± 10 ppm, 0-50C, 5 ppm/yr
Bandwidth RBW Selections 3kHz, 30kHz, 300kHz, 4MHz,
RBW Accuracy 15 %
Video Bandwidth 10Hz to 1MHz in 1-3 steps
Sweep time 100 ms to 25.6 s
Amplitude Input Range -100dBm to +20dBm, 1M to 2.5GHz
(@3k RBW) -95dBm to +20dBm, 2.5G to 2.7GHz
-70dBm to +20dBm, 150k to 1MHz
-60dBm to +20dBm 50k to 150kHz
Reference Level Range -30 to +20dBm, overload protected
Accuracy ± 1.5dB @100MHz
Frequency Flatness ±1.5dB,
Display Range Linearity ± 1.5dB over 70dB
Overload protection +30dBm, ±25VDC
Average Noise Floor -130dBm/Hz, 1MHz to 2.5GHz
-125dBm/Hz, 2.5GHz to 2.7GHz
-105dBm/Hz, 150kHz to 1MHz,
-95dBm/Hz, 50k to 150kHz
Harmonic Distortion <-60dBc @-40dBm Input
Non-harmonic Spurious <-60dB, down from Ref. Level 150k to
2.7GHz
Third Intermodulation <-70dBc @-40dBm Input, 2 MHz apart
Input RF input
Overload Protection +30dBm, ±25VDC
Impedance: 50 Ohm nominal
Return loss <1.5:1 @0dBm Ref. Level
Connector Type N Female
External reference input 1M, 1.544M, 2.048M, 5M, 10M, 10.24M,
13M, 15.36M, 15.4M, 19.2M
Output Reference clock output 10MHz
Features Marker
Mode Normal and Delta mode
Number Up to 10 in Multi Marker mode
Peak Search To Center, Next Peak, Peak Right/ Left and
Peak Track
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2.7GHz Spectrum Analyzer Service Manual
Features Trace
Number Two, Tr A and B for display memory
Functions Peak Hold, Average, Freeze, Math.
Detect: Sample, Peak+, AVG1/2/3, Quasi-peak
Power measurement ACPR x 2, OCBW, Channel power
Limit Line
Number Two, high and low
Function Pass/Fail test, Edit: Insert, Delete, Undo
Trigger
Mode Continuous, Single
Source Video, External (0~5V rising edge)
Setting Trigger delay, Trigger Frequency
Display Contrast, Backlight ON/OFF, Invert Screen.
Split Window: Upper and Lower
Save/Recall 100 traces and Setup
Calendar and clock
Interface RS232C,
Cal Signal 100MHz, -30dBm
General Display: 640 x 480 high resolution graphical LCD,
B&W
Weight: 4.5kg without options
Size 330 (W) x 170(H) x 340(D) mm
Options
Opt.01 Frequency Range 9kHz to 2.7GHz
Tracking Amplitude Range -50dBm to 0 dBm
Generator Amplitude accuracy ±1dB @100MHz, 0dBm
Amplitude flatness ±1.5dB @0dBm
Harmonics <-30dBc
Reverse Power +30dBm
Impedance 50 Ohm nominal
Return Loss <1.5:1
Opt.02 DC/AC/Battery Power AC 100 to 240V, DC-12V and 10.8V Li Ion
Supply Operation and battery pack battery pack
Opt. 03 ¡Ó 1ppm Stability ¡Ó 1ppm 0~50°C, ¡Ó 1ppm/year
Opt.06 GPIB interface IEEE 488 bus
Opt. 07 Soft Carrying Case GSC-001
Opt. 08 General Kit set ADP-002: SMA-N adapter x 2
ATN-100: 10dB attenuator x 1
GTL-303: RF cable (SMA, RD316, 60cm) x2
GSC-002: Kit box x1
Opt. 09 CATV Kit set ADP-001: N-BNC adapter x 2
ADP-101: 50£[ - 75£[ adapter x 2
GTL-304: RF cable (N-N, RG223, 30 cm) x 2
GSC-003: Kit box
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2.7GHz Spectrum Analyzer Service Manual
Opt. 10 RLB Kit set GAK-001: Termination 50£[ x1
GAK-002: Cap with chain x1
GTL-302: RF cable (N-N, RG223, 30cm) x1
GSC-004: Kit box x1
Opt. 11 DC Power line GTL-401: DC power cord with DC jack and
lighter plug, 5A.
Table 2.1 GSP827Specifications
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2.7GHz Spectrum Analyzer Service Manual
3.0 Specification Verification
This procedure is referred when the regular verification is performed. The required
verification equipments are listed as following.
Calibration application Equipment Q'ty
Spectrum Analyzer RF Signal Generator: 1
10MHz to 2.7GHz
Power to +17dBm
Phase Noise<-100dBc/Hz@10kHz offset
Output Return Loss <-15dBRL
High Stability (1ppm) option
Amplitude accuracy is well-calibrated at +/-
0.2dB.
Tracking Generator RF Power Meter with sensor Head 1
(optional) Frequency: 25MHz to 2.7GHz
Accurate to +/-0.2dBm at 10dBm
Spectrum Analyzer 1
9k to 2.7GHz
Misc. RF cable and N-SMA adapter Various
Table 3.1 Equipment for Specification verification
Recommendations
1. In order to get accurate results, it is recommended to measure the loss of RF cable
before practice the amplitude related tests. Calculate the accurate result by the
following equation.
Reading_true= Reading + Cable loss
Replace the Reading of all tests with Reading_true.
2. The semirigid or RD316 equivalent cables are recommended to in use.
3. BNC connector CANNOT be used in this verification because of the poor high
frequency characteristics. SMA, N type connectors are recommended for this
application.
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2.7GHz Spectrum Analyzer Service Manual
3.1 Frequency Accuracy- Center and Span.
Testing Connection
Signal Generator DUT
Figure 3.1 Testing connection of Frequency accuracy test
Reference Table
Table 3.1. (See section 3.11 Recording Tables)
Procedures
1. Set the DUT Reference Center Frequency to 1GHz, Span to 200kHz, Reference
Level to 0dBm, BW and for AllAuto mode.
Frequency >> Center >> 1 GHz
Span >> Span >> 2 0 0 kHz
Amplitude >> Ref Level >> 0 dBm
BW >> ALL Auto
2. Set the Signal Generator to 1000MHz and 10dBm output.
3. Push Peak Search to find the peak signal. Record the frequency reading of the
peak signal.
Peak Search
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2.7GHz Spectrum Analyzer Service Manual
3.2 RBW Accuracy
Testing Configuration
Signal Generator DUT
Figure 3.2 Testing connection of RBW accuracy test
Reference Table
Table 3.2. (See section 3.11 Recording Tables)
Procedures
1. Set the DUT to 100MHz center, 10dBm reference level, RBW to manual
mode.
Frequency >> Center >> 1 0 0 MHz
Amplitude >> Ref Level >> - 1 0 dBm
BW >> RBW Manu
2. Connect the signal generator and adjust the power level around 10dBm until
the peak of the displayed just touches the top graticule.
3. Set the DUT to span = 10kHz and RBW to 3kHz.
Span >> Span >> 1 0 kHz
BW >> /
4. Adjust the generator frequency to give a peak marker reading.
5. Record the frequency and the marker reading (dBm) at which the peak occurs.
6. Tune the SG amplitude 3dB lower. Record the marker response in this case.
7. Tune the SG amplitude back to 10dBm.
8. Vary the generator frequency upwards until the 3dB response marker reading is
duplicated to within 0.1dB. Record this generator frequency as the upper
frequency fup.
9. Vary the generator frequency downward until the 3dB response marker reading
is again found below the peak response of the filter. Record this generator
frequency as the lower frequency fdn.
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2.7GHz Spectrum Analyzer Service Manual
10. Subtracting the two frequencies by the above method gives the RBW.
11. Repeat the above steps for each filter 30kHz (100kHz), 300kHz (1MHz) and
4MHz(10MHz).
Span >> Span >> 1 0 0 kHz
BW >> / .
Span >> Span >> 1 MHz
BW >> / .
Span >> Span >> 1 0 MHz
BW >> / .
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2.7GHz Spectrum Analyzer Service Manual
3.3 Amplitude Accuracy
Testing Configuration
Signal Generator DUT
Figure 3.3 Testing connection of Amplitude accuracy test
Reference Table
Table 3.3. (See section 3.11 Recording Tables)
Procedures
1. Set the DUT to 100MHz center, 100kHz span, 0dBm reference level.
Frequency >> Center >> 1 0 0 MHz
Span >> Span >> 1 0 0 kHz
Amplitude >> Ref Level >> 0 dBm
BW >> ALL Auto
2. Turn off the internal reference signal.
System >> Cal Sig OFF
3. Connect to signal generator which output is 100MHz and 10dBm power.
4. Record the level reading of peak.
5. Repeat the above steps for each filter 30kHz(1MHz), 300kHz(10MHz) and
4MHz(100MHz).
Span >> Span >> 1 MHz
>> 1 0 MHz
>> 1 0 0 MHz
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2.7GHz Spectrum Analyzer Service Manual
3.4 Reference Level Attenuation Error
Testing Configuration
Signal Generator DUT
Figure 3.4 Testing connection of Reference Level accuracy test
Reference Table
Table 3.4. (See section 3.11 Recording Tables)
Procedures
1. Set DUT to CENTER=110MHz, SPAN = 10MHz, Reference Level=20dBm.
Frequency >> Center >> 1 1 0 MHz
Span >> Span >> 1 0 MHz
Amplitude >> Ref Level >> 2 0 dBm
BW >> ALL Auto
2. Set the SG frequency = 50MHz, output level = 10dBm (10dB less of DUT
reference level).
3. Record the peak reading by PeakSearch.
4. Decrease the SG output level and Reference Level of DUT 10dB simultaneously
till SG reaches 40dBm and Reference Level reaches 30dBm, repeat step 1 to
3.
Amplitude >> Ref Level >> (to select 10dBm)
>> (to select 0dBm)
>> ...
>> (to select 30dBm)
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2.7GHz Spectrum Analyzer Service Manual
3.5 Amplitude level Linearity
Testing Configuration
Signal Generator DUT
Figure 3.5 Testing connection of Amplitude Linearity accuracy test
Reference Table
Table 3.5. (See section 3.11 Recording Tables)
Procedures
1. Set DUT to CENTER=110MHZ, SPAN set to 100kHz for 3kHz RBW,
Reference Level=-10dBm.
Frequency >> Center >> 1 1 0 MHz
Span >> Span >> 1 0 0 kHz
Amplitude >> Ref Level >> - 1 0 dBm
BW >> ALL Auto
2. Set the SG frequency at 110MHz, output level at 1dBm less of DUT reference
level.
3. Record the Peak reading by pushing PeakSearch.
4. Decrease the SG output level 10dB and record the Peak reading till 80dBm.
5. Repeat the above steps for each filter 30kHz(1MHz), 300kHz(10MHz) and
4MHz(100MHz). Note the levels of the bottom of 30k, 300k and 4M column
are 70dBm, -60dBm and 50dBm respectively.
Span >> Span >> 1 MHz
>> 1 0 MHz
>> 1 0 0 MHz
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2.7GHz Spectrum Analyzer Service Manual
3.6 Frequency Flatness
Testing Configuration
Signal Generator DUT
Figure 3.6 Testing connection of Frequency Flatness test
Reference Table
Table 3.6. (See section 3.11 Recording Tables)
Procedures
1. Set DUT to CENTER=10MHZ, SPAN = 10MHz, Reference Level=-10dBm..
Frequency >> Center >> 1 0 MHz
Span >> Span >> 1 0 MHz
Amplitude >> Ref Level >> - 1 0 dBm
BW >> ALL Auto
2. Set the SG frequency at 50MHz, output level at -11dBm.
3. Record the Peak reading by pushing PeakSearch.
4. Decrease the SG output level 10dB and record the Peak reading till 80dBm.
5. Repeat the above steps for increasing frequency by 100MHz step, like 110, 210,
310, till 2610MHz.
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2.7GHz Spectrum Analyzer Service Manual
3.7 TG Output Accuracy (optional)
Testing Configuration
DUT
Power Meter
-3.18 dBm
Sensor
Figure 3.7 Testing connection of TG output level accuracy test
Reference Table
Table 3.7. (See section 3.12 Recording Tables)
Procedures
1. Set DUT CENTER=310MHZ, SPAN at Zero Span.
Frequency >> Center >> 3 1 0 MHz
Span >> Zero Span
2. Set TG ON, Level to 0dBm, Offset at 0 kHz.
Option >> TG >> TG ON
>> TG Level >> 0 dBm
>> Offset >> 0 kHz
3. Use Power meter to measure the output level and record the reading.
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2.7GHz Spectrum Analyzer Service Manual
3.8 TG Attenuation Accuracy of Output (optional)
Testing Configuration
DUT
Power Meter
-3.18 dBm
Sensor
Figure 3.8 Testing connection of TG attenuation accuracy test
Reference Table
Table 3.8. (See section 3.11 Recording Tables)
Procedures
1. Set DUT CENTER=310MHZ, SPAN to Zero span.
Frequency >> Center >> 3 1 0 MHz
Span >> Zero Span
2. Set TG ON, Level to 0dBm, Offset at 0 kHz.
Option >> TG >> TG ON
>> TG Level >> 0 dBm
>> Offset >> 0 kHz
3. Use Power meter to measure the output level and record the reading.
4. Change the TG output level to 10, -20, -30, -40, -50dBm and repeat step 1 to
3 respectively.
Option >> TG Level >> - 1 0 dBm
>> ...
>> - 5 0 dBm
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2.7GHz Spectrum Analyzer Service Manual
3.9 TG Output Flatness (optional)
Testing Configuration
DUT
Power Meter
-3.18 dBm
Sensor
Figure 3.9 Testing connection of TG output flatness test
Reference Table
Table 3.9. (See section 3.11 Recording Tables)
Procedures
1. Set DUT CENTER=50MHZ, Span to Zero Span.
Frequency >> Center >> 5 0 MHz
Span >> Zero Span
2. Set TG ON, Level to 0dBm, Offset at 0 kHz.
Option >> TG >> TG ON
>> TG Level >> 0 dBm
>> Offset >> 0 kHz
3. Use Power meter to measure the output level and record the reading.
4. Change the CENTER to 100, 200, ... 2700MHz and repeat step 3
respectively.
Frequency >> Center >> 1 0 0 MHz
>> 2 0 0 MHZ
>> ...
>> 2 7 0 0 MHz
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2.7GHz Spectrum Analyzer Service Manual
3.11 Recording Tables
Table 3.1 Frequency Accuracy-Center and Span
Center Span Freq. In. Freq. Error Error Spec. Note
MHz MHz Reading (MHz) (ppm)
1000 200kHz/div 1000 ±10ppm
Table 3.2 RBW Bandwidth
Span(RBW) 3dB Reading fup fdn fup-fdn Error Spec. Note
(dBm) (Hz) (%)
10KHz(3KHz) ±15%
100KHz(30KHz) ±15%
1MHz(220KHz) ±15%
10MHz(4MHz) ±15%
Table 3.3 Amplitude accuracy test
DUT SPAN(RBW)
10KHz(3K) 100KHz(30K) 1MHz(220K) 10MHz(4M)
SG Level (dBm) -10 -10 -10 -10
DUT Reading
Error
Spec. ± 1 dB ± 1 dB ± 1 dB ± 1 dB
Note
Table 3.4 Reference Level Attenuation Accuracy
Reference 20 10 0 -10 -20 -30 Error Spec. Note
Level (dBm) (pk-pk)/2*
SG level 10 0 -10 -20 -30 -40 --- ---
dBm
DUT ¡Ó 1.5dB
Reading
* : Take the (Max. Peak Min. Peak)/2 to be the measurement result, Error. All the
following test results should apply to the same concept.
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2.7GHz Spectrum Analyzer Service Manual
Table 3.5 Amplitude level Linearity
SG Output Reference SPAN(RBW)
Level (dBm) Level (dBm) 100kHz(3k) 1MHz(30k) 10MHz(300k) 100MHz(4M)
-11 -10
-21 -10
-31 -10
-41 -10
-51 -10
-61 -10
-71 -10
-81 -10
Error (pk-pk)/2
Spec. ¡Ó 1.5dB ¡Ó 1.5dB ¡Ó 1.5dB ¡Ó 1.5dB
Note
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2.7GHz Spectrum Analyzer Service Manual
Table 3.6 Frequency Flatness Test
Frequency SG Level Reading Error Spec. Note
(MHz) dBm dBm (pk-pk)/2
10 -11 ± 1.5 dB
110 -11
210 -11
310 -11
410 -11
510 -11
610 -11
710 -11
810 -11
910 -11
1010 -11
1110 -11
1210 -11
1310 -11
1410 -11
1510 -11
1610 -11
1710 -11
1810 -11
1910 -11
2010 -11
2110 -11
2210 -11
2310 -11
2410 -11
2510 -11
2610 -11
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2.7GHz Spectrum Analyzer Service Manual
Table 3.7 TG Output Accuracy Test (optional)
TG Setting Reading Error Spec. Note
80MHz, 0dBm ±1 dB
Table 3.8 TG Attenuation Accuracy Test (optional)
TG setting MHz 310 310 310 310 310 310
TG setting (dBm) 0 -10 -20 -30 -40 -50
Reading (dBm)
Error
Spec. ±1.5 dB
Note
Table 3.9 TG Output Flatness Test (optional)
TG setting MHz 50 100 200 300 400 500 600 700 800 900 1000
TG setting (dBm) 0 0 0 0 0 0 0 0 0 0 0
Reading (dBm)
Error
Spec. ±1.5 dB
Note
TG setting MHz 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100
TG setting (dBm) 0 0 0 0 0 0 0 0 0 0 0
Reading (dBm)
Error
Spec. ±1.5 dB
Note
TG setting MHz 2200 2300 2400 2500 2600 2700
TG setting (dBm) 0 0 0 0 0 0
Reading (dBm)
Error
Spec. ±1.5 dB
Note
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2.7GHz Spectrum Analyzer Service Manual
4.0 Operation Theory
4.1 General Description
GSP827 is basically composed of RF, LO2, IF DSP, mother board and power
modules for basic unit. Tracking Generator, DC/AC/Battery operational power supply,
1ppm stability time base and GPIB are the optional modules. Refer to following
sections for more detailed.
4.2 RF Module
RF module converts the 9kHz to 2.7GHz input signal to 452MHz IF signal for
IF module. It includes attenuation, LO1, First and second IF stages, and 100MHz
calibration signal. The block diagram is described in figure 4.1 as below.
RF input FL1,
452MHz, to
IF Module
RV1 from LO2
PLL
B 100MHz, from IF
RV2
Figure 4.1 Block diagram of RF module
4.3 LO2 module
LO2 module is to generate a fixed LO signal which is fed into RF module. Mixing
with IF1 signal, the second IF signal 452MHz comes out from RF module. The block
diagram is described in figure 4.2.
100MHz, from IF
B x 32 LO2 output
x 1/4 25MHz clock
Figure 4.2 Block diagram of LO2
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2.7GHz Spectrum Analyzer Service Manual
4.4 IF module
IF module includes time base generator, RBW filters, log amplifier and VBW
filters. It converts the 452MHz IF signal to DC voltage to DSP module to be
sampled. Figure 4.3 is the block diagram to illustrate the concept.
4ML22~L25 4M Log Amp
dBm
L12, L15,
AGC L48~L50
From 300k Vdc
RF RV5
From
DSP8 bit L45, L81 mV
DAC 1,024
30k RV4
RV6
VC259, L43 10 bit
3k ADC
Vdc
0
Figure 4.3 Block diagram of IF module
4.5 DSP module
DSP module samples the signal from IF module and display the result as a trace
on the LCD module.
DSP Code/Data
memory
Bus Graphic LCD
I/F controller
Keypad
EPLD &
Control
Mother
XCVR board
RS232
Figure 4.4 Block diagram of DSP module
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2.7GHz Spectrum Analyzer Service Manual
4.6 Mother board
All modules are modularized designs and stand on mother board. Mother board
basically carries the power and control signals between DSP and the other modules.
4.7 TG (option)
Tracking Generator generates sweep signal at TG output connector. The TG
output frequency is identical and synchronized to spectrum analyzer Center Frequency
and Span setting. Figure 4.5 shows the block diagram.
LO3 LO2 LO1
IF3
Output
C D
From CPU DAC RV1
AGC
Figure 4.5 Block diagram of TG module
4.8 Power supply module (standard)
The power supply module is switching mode power supply. The input is available
for 90~260 VAC input to generate +5V, -5.7V, +9V and +24V DC voltage sources.
4.9 DC/AC/Battery operational power supply (option)
This is also power supply module but differs from section 4.8 power module. This
module allows AC, DC and battery operations. It consists of AC to DC, DC to DC and
charger circuitries. Refer to section 7.4 and figure 7.3 for the block diagram.
4.10 Higher stability time base (option)
It is an option attached on IF module to perform the measurement with higher
stability time base.
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2.7GHz Spectrum Analyzer Service Manual
5.0 Trouble shooting guide
In this chapter, we will start form system diagnosis that explains the given
information of self diagnosis on display. And then a diagnosis map is given to help
developing a strategy for trouble shooting. A spare part list is attached as the end of this
chapter.
5.1 System Diagnosis
5.1.1 Diagnosis information
1. Push System >> System Config , the system configuration with diagnosis
information will appear on the display as below.
System Configuration
Serial Number: D100001
Software Version: 01. 03b
Release Date: 07/22/03
Firmware version: 2.0
Options: TG,
LO Lock Status: LO1 LOCKED
LO3 LOCKED
Reference Signal: INTERNAL STD
Reference Status: LOCKED
Figure 5.1 Display of system configuration
2. Besides, the LO lock status, reference signal and reference lock status will also
dynamically display on the top of graticule.
Diagnosis information
SAT JAN 28, 2003 14:30:25
INT:REF
Ref Lvl: -30.0 dBm AMPL CAL Center
-30.0
-40 0
Figure 5.2 Dynamic diagnosis information
The following sections will explain the follow-up of every diagnosis results.
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2.7GHz Spectrum Analyzer Service Manual
5.1.2 LO1 Unlocked.
1. Try the other frequencies. The following 3 frequencies are typical for testing,
100MHz, 500MHz and 2GHz
2. Try the wider or narrower spans to check if it remains unlocked.
3. Refer to section 6.0 and 6.8 to check LO1 data. The values of the 8 indexes
should not be the same number. Try to adjust the LO1 value. Record the original
values before adjust it.
4. Refer to section 5.5 to track the problem.
NOTE: Step 3 and 4 should be practiced by authorized personnel only.
5.1.3 LO3 Unlocked
Refer to section 5.5 to track the problem or send the unit back to factory.
5.1.4 Reference Unlocked.
Refer to section 5.5 to track the problem or send the unit back to factory.
5.1.5 External Reference Unlocked
1. Make sure the external reference clock is in the correct selection.
Press Option >> ExtRefFreq , use or key to select the correct frequency.
2. Otherwise refer to section 5.5 to track the problem or send the unit back to
factory.
5.2 No Display when Power Up
When the STBY key on front panel is pushed, the power indicator should turn into
green. If neither backlight nor data is on the display perform the following checks.
1. Turn on the backlight and adjust LCD contrast. It is done as follows.
Turn on backlight: Display >> BkLight ON
Adjust LCD contrast: Display >> LCD Cntrst >> Rotate Fly Wheel.
2. If backlight can not be on but data appears, check the DC/AC converter of back
light power
3. If data can not appear on LCD, refer to section 7.0 for opening the unit to
perform the following check.
4. Check the power presented on J12 of mother board. The color and the voltages
are listed below.
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2.7GHz Spectrum Analyzer Service Manual
Color Green Brown Yellow Black Black Red
Voltage (DCV) +24V +9V -5.7V GND GND +5V
Table 5.1 Voltage of power connector on MB
5. Check if the LO1 works or not. Check the LO1 status indicator D5 on RF module.
Refer to section 8.2.1 and figure 8.3 for the location of D5.
6. If D5 lights up in step 2, check if the LCD cable on DSP module is loose. Turn
off the unit and reconnect the LCD cable carefully.
7. If D5 does not light in step 2, refer to section 5.5 to track the problem or send the
unit back to factory.
NOTE: Opening the case should be practiced by authorized personnel only.
5.3 No signal on Display
If only noise floor appear on the LCD, or the signal is much lower than it is
supposed to be, a series of checks need to be done. Refer to section 5.5 to track the
problem or send the unit back to factory.
5.4 Fail to meet Specification
If the unit fails to meet the specification, in most of case, it needs to be recalibrated
or readjusted. Here is a table for the category of fails and adjustment supposed to do.
Phenomenon Calibration Adjustment
Level deviated slightly for all RBW Cal. (section 6.4) No
RBWs, reference levels and
frequencies.
Frequency response is not flat FreqResp Cal. (section 6.3) IF adjustment. (section 8.2.3)
Log linearity is not linear enough IFGainFine Cal. (section 6.2) IF adjustment. (section 8.2.3)
TG output level is not correct TG Fine Level Cal. (section TG RV1. (section 8.3)
6.3.3)
TG output frequency response is TG Freq. Cal. (section 6.3.2) No
not flat enough.
Calibration signal level is not right No RF RV2 (section 6.7)
Table 5.2 Cross reference of Failure and calibration and Adjustment
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2.7GHz Spectrum Analyzer Service Manual
5.5 Troubleshooting Map
This map shows how to track the root cause by series of observations. The
principle is to minimize the chance of opening the unit. Once the case or the individual
modules need to be open, refer to chapter 7, 8 for the information.
Start
LO1 lock?(1) N
Change band(2)
LO3 lock? (1) N
Open IF
N
Module Other bands
lock?
Other RBWs ok?
Open IF 500MHz N
N Open Outer
Module signal ok? Open RF
Module case
Turn 100MHz
Check
CalSig ON. Check Q7
RBW path Set Zero
Q8 Check the Adjust RV1
Span (section 8.0,
unlocked
VCO, SWs, 8.2.1)
Regulator
CalSig appears
normally? 26.6MHz Open RF
Open RF signal ok?
Module
Module
N N
Check U7, Check U6,
Check input AD9850, DDS Check U9
Caps, limiters. OP27 OPA 227
Changing Ref.Lvl N
will change trace
accordingly? Open RF
Module