aor_sr2000_sm.pdf

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1、 FFT FREQUENCY MONITOR SR2000 Service Manual 2-6-4 Misuji, Taito-ku Tokyo 111-0055 Japan AOR, LTD. AOR, LTD. 2005.3.16 1 1.Circuit Description Refer to a attached SR2000 MAIN Unit Block Diagram. 1.1.MAIN Unit 1.1.1.Front end circuit block The incoming RF signal from RF IN is fed to 10.7MHz +/- 5MHz

2、BPF(Band Pass Filter) via buffer amplifier. The output signal of BPF is amplified or attenuated by LNA (Low Noise Amplifier), and is fed to two DBMs (Double Balanced Modulator). These signals are converted to two AF (Audio Frequency) signals, one side is real part signal, the other side is imaginary

3、 part signal. These AF signals are fed to each 80kHz LPF (Low Pass Filter) and transfer digital signals by ADC (Analog to Digital Converter). 1.1.2.DDS circuit block The DDS (Direct Digital Synthesizer) circuit block supply two sine waves which is orthogonal with each other to two DBMs. These RF sig

4、nals are fed to DBMs via 60MHz LPF and RF amplifier. 1.1.3.Digital signal processing block Two digital signals converted by ADCs are fed to DSP (Digital Signal Processor) via FPGA (Field Programmable Gate Array). 1.1.4.User interface and control block User interface block is constituted a CPU on the

5、 panel board, a rotary encoder, and 26 tact switches. The CPU on the panel board is a slave of the CPU on the main board, and send to it from user request. The CPU on the main board control both the entire MAIN Unit and RF Unit. 1.1.5.Power circuit block Supplied power is first fed to ferrite chip,

6、where this chip prevent from spreading spurious. The power is led to switch control via fuse and back current prevented diode, and generated various voltage. 2 1.2.RF Unit Refer to a attached “RFU Unit BLOCK DIAGRAM”. 1.2.1.Overview The RF unit for SR2000 is wide range communications receiver operat

7、ing up to 3,000MHz. It has three pieces of Printed Circuit Board inside; 1. Front-End and 2nd, 3rd Mixer stage: SR2K-FRMX 2. 1st and 2nd local oscillator: SR2K-OSC 3. 2nd IF amplifier, 3rd IF detector, Audio out, CPU and Power Supply: SR2K-IFCP 1.2.2.RF circuit. Signal input from antenna connector i

8、s switched to a selected band pass filter and RF amplifier on SR2K-FRMX. Band Pass Filter: 1. 25 60 MHz 2. 60 108 MHz 3. 108 142 MHz 4. 142 174 MHz 5. 174 224 MHz 6. 224 335 MHz 7. 335 480 MHz 8. 480 690 MHz 9. 690 1030 MHz 10. 1030 1696 MHz 11. 1696 3000 MHz The signal is fed to the next RF amplifi

9、er and attenuator, which can be switched on/off for better performance, on SR2K-FRMX circuit board. 2 pieces RF amplifiers are provided for 2 frequency bands; 1. 25 1696 MHz 2. 1696 3000 MHz The signal in the above frequency band is mixed with 1st local oscillator and will be made 2 kinds of 1st IF

10、frequency (265.2 MHz or 755.2 MHz) as refer to the chart of “RECEIVE VS 1st LOCAL OSC FREQUENCIES.” 1.2.3.IF circuit The IF signal is amplified and fed to the 2nd mixer for converted to 10.7 MHz IF. The 10.7 MHz IF signal is switched to a selected 10.7 MHz band width filter and amplified. The 10.7 M

11、Hz signal is mixed with 10.245 MHz and made 455 kHz IF. The 455 kHz IF signal is fed to FM detector (IC: TA31137FN) for FM mode, WFM and AM detector (IC: CXA1611N). The detected audio signal is fed to the Audio Power amplifier (LA4425A). 3 1.2.4.1st local oscillator The 4 pieces of VCO provide the 1

12、st local frequency controlled by PLL system. The reference frequency is 14.4 MHz which is temperature compensated by TCXO. The frequency range of VCOs are; 1. 265 318 MHz 2. 318 382 MHz 3. 382 458 MHz 4. 458 550 MHz The above frequency may be multiplied two or four for higher receiving frequency. 1.

13、2.5.2nd local oscillator The 2 pieces of VCO makes 2nd local frequency, 744.5 MHz or 254.5 MHz. These frequencies are controlled by PLL system. The reference frequency is 21.4 MHz provided from DDS (Direct Synthesizer System): AD9851. This reference frequency will be changed a little for small steps

14、 of 1 Hz, 100 Hz, 8.33 kHz and so on. 4 2.Required test and adjustment equipment Required equipment for test and adjustment is the followings. 2.1.MAIN Unit 1. DC ammeter. It can measure up to 2A. 2. DC voltmeter. It can measure up to 20V, and can read in 0.05V step. 3. AC voltmeter. It can measure

15、up to 1000Vp-p. 4. Stabilized DC power supply. It can be output that voltage is DC12V, and maximum output current is about 2A. 5. Detailed phillips head screw driver. 6. Phillips screw driver. 7. Personal computer. It has at least one RS232C port. 8. Signal generator. It can generate sine wave 10.7M

16、Hz +/- 5MHz and 45.05MHz +/- 5MHz. 9. RF Unit. SR2000s RF Unit which confirmed normal operation. 10. Coaxial cable Its impedance is 50 ohm, one side has BNC-P (Male) connector, and the other side is depend on signal generator. 11. RS-232C straight type interface cable (female - female). It has two D

17、SUB-9 female connectors between full connection straight type. 12. RS-232C straight type interface cable (male - male). It is SR2000s accessory or equivalent of this. 13. Digital counter It can measure up to about 10MHz, and can read in 1Hz step. 5 3.Test 3.1.Test of MAIN Units consumption current 1

18、. Connect the SR2000 and peripheral equipment in accordance with the following figure. Fig. 1: Connection diagram outline of DC power supply and DC ammeter. Fig. 2: Connection diagram (View from SR2000 rear side). 2. Check the consumption current less than 950mA. Annotation: The cables that the conn

19、ectors between REMOTE and RX CTR use the accessories of SR2000. 6 3.2.Test of spectrum 1. Connect the SR2000 and peripheral equipments in accordance with the following figure. Fig. 3: Connection diagram (View from SR2000 rear side). 3.2.1.Case of no signal input 1. Turn off the SR2000 if it is runni

20、ng. 2. Keep pushing the SR2000s 3 and 6, turn on it. 3. As the opening screen appears, keep pushing above mentioned keys still the characters EEPROM initialized is found. 4. After the SR2000 has started, wait about 10 seconds. 5. Push the keys FUNC - MK.F - CPEAK in order. 6. Check the value of Mark

21、er intensity at Maker information is less than -88dBm. 3.2.2.Case of 10.7MHz signal input 1. Connect the SR2000s RF IN terminal and the signal generators output terminal by used of coaxial cable. 2. Set the signal generator the followings. Frequency 10.7MHz Intensity -60dBm Modulation None 3. Check

22、the value of Marker intensity at Maker information is the followings. Marker frequency 87.96875MHz 88.03125MHz Marker intensity -60dBm +/-2dBm 7 3.2.3.Case of 5.7MHz signal input 1. Set the signal generator the followings. Frequency 5.7MHz Intensity -60dBm Modulation None 2. Check the value of Marke

23、r intensity at Maker information is the followings. Marker frequency 83.00000MHz 88.03125MHz Marker intensity -60dBm +/-2dBm 3.2.4.Case of 15.7MHz signal input 1. Set the signal generator the followings. Frequency 15.7MHz Intensity -60dBm Modulation None 2. Check the value of Marker intensity at Mak

24、er information is the followings. Marker frequency 92.96875MHz Marker intensity -60dBm +/-2dBm 8 3.3.Receivers Spectrum test 1. Connect the SR2000 and peripheral equipments in accordance with the following figure. Fig. 4: Connection diagram (View from SR2000 rear side). 2. Specify an appropriate fre

25、quency by the SR2000, check the spectrum on the LCD of it. 9 3.4.Communication test between PC and the MAIN Unit 1. Connect the SR2000 and peripheral equipments in accordance with the following figure. Fig. 5: Connection diagram (View from SR2000 rear side). 2. Set the PCs communication software the

26、 followings. Baud speed 115200bps Data length 8 bit Parity None Stop bit 2 bit Flow control RTS / CTS As the SR2000 do not return entered character string, set the parameter local echo of the PCs communication software to available as necessary. 3. Check the return value when the following character

27、 sting is input. VR Read out the firmware version CF Read out the center frequency MHz FP Read out the frequency span MHz 10 4.Adjustment 4.1.Calibration of spectrum 1. Remove the upper cover and the RF Unit of the SR2000. 2. Connect the SR2000 and peripheral equipments in accordance with the follow

28、ing figure. Fig. 6: Connection diagram (View from SR2000 rear side). 3. Keep pushing the SR2000s 3 and 6, turn on it. 4. As the opening screen appears, keep pushing above keys still the strings EEPROM initialized is found. 5. After the SR2000 has started, set the frequency span 500kHz, and turn off

29、it once. 6. Keep pushing the SR2000s 1, 5, 9, and left soft key . As the opening screen appears, keep pushing above keys still the characters Calibration Mode is found. 7. Set the signal generator the followings. Frequency 10.71MHz Intensity -40dBm Modulation None 7. Check that one or two (large and

30、 small) spectrums are appeared on SR2000s LCD. If two spectrums are appeared, large spectrum is real, and small spectrum is image. 8. Rotate the SR2000s dial in order that the small (image) spectrum is least. 9. Next, Set the signal generator the followings. Frequency 10.79MHz Intensity -40dBm Modul

31、ation None 9. One or two spectrums are appeared on SR2000s LCD again. 10. Rotate the SR2000s dial in order that the small (image) spectrum is least too. 11. Repeat above items 5 to 10 in order that the result of item 7 and 9 are about equal. After the work is complete, push the keys kHz and MHz of t

32、he SR2000. 11 12. Turn off the SR2000. 4.2.Checking and adjustment of internal voltage at MAIN Unit 1. If the SR2000 is running, turn off it and disconnect all connected cables. 2. Remove the upper and under cover of the SR2000. 3. Remove the RF Unit of the SR2000. 4. Remove the Front panel of the S

33、R2000. 5. Disconnect the harness of the main boards CN10. 6. Reassemble the Front panel of the SR2000. 7. Connect the SR2000 and peripheral equipments in accordance with the following figure. Fig. 7: Connection diagram (View from SR2000 rear side). 8. Measure and check each TP. Each TPs voltage is t

34、he followings. TP1 6.0 7.0V TP2 4.9 5.5V TP3 -4.75 -5.25V TP4 3.05 3.55V TP5 2.25 2.75V TP6 4.75 5.25V TP7 3.5 3.8V TP8 3.1 3.5V TP9 16.0 18.0V TP10 -14.0 -16.0V TP11 4.9 5.5V TP12 -6.5 -7.5V TP14 3.6 4.4V 9. If the measured each TPs voltage and above mentioned is different, adjust by chip volume. A

35、djustment process are the followings. a. While measure the TP1 voltage, turn chip volume VR1. b. Then, turn chip volume VR2 while measure the TP voltage. 12 Fig. 8: TP positions. 13 4.3.Checking and adjustment of internal clock at MAIN Unit 1. If the SR2000 is running, turn off it and disconnect all

36、 connected cables. 2. Remove the upper and under cover of the SR2000. 3. Connect the SR2000 and peripheral equipments in accordance with the following figure. Fig. 9: Connection diagram (View from SR2000 rear side). 4. Measure and check either the both ends of R325. This point of frequency is the fo

37、llowings. R325 28.63631 28.63641MHz a. If the above value is different, adjust by the chip trimmer capacitor. The chip trimmer capacitor exists on the MAIN board solder side. 14 5.PCB silk errata At serial No. 0908005109080100, the PCB of MAIN Unit has the following mistakes. ! MAIN board. 1. The si

38、lk “C245” is duplicate. The solder sides is correct, and the part sides is incorrect. It is “C247” by rights. 2. The silk “Q63” and “Q64” dont exist on the solder side in spite of the existence 3. The silk “C184” and “R229” pass each other. ! PANEL board. 1. The silk “U2” doesnt exist on the solder

39、side in spite of the existence. For each part position, please refer the following figure. Sorry for your inconvenience. Fig. 10: PCB errata (Part side) 15 Fig. 11: PCB errata (Solder side) 16 6.Attached documents ! RECEIVE VS 1st LOCAL OSC FREQUENCIES # RF Unit ! DC Voltages # RF Unit ! Block diagr

40、am # Main Unit # RF Unit ! Partlist # Main Unit # RF Unit ! Detail of parts # Main Unit # RF Unit ! Circuit diagrams # Main Unit # RF Unit ! PCB parts layout # Main Unit # RF Unit ! Disassembly drawings RECEIVE VS 1st LOCAL OSC FREQUENCIES RX FREQ.1st LOCAL FREQ.STEP1st IF FREQ.1st VCO MUTIPLY 2nd V

41、CO 25MHz - 85MHz290.2MHz - 350.2MHz50KHz265.2MHz +AX 1A 85MHz - 170MHz350.2MHz - 435.2MHz50KHz265.2MHz +BX 1A 170MHz - 225MHz435.2MHz - 490.2MHz50KHz265.2MHz +CX 1A 225MHz - 330MHz980.2MHz - 1085.2MHz100KHz755.2MHz +CX 2B 330MHz - 380MHz595.2MHz - 645.2MHz50KHz265.2MHz +DX 1A 380MHz - 435MHz645.2MHz

42、 - 700.2MHz100KHz265.2MHz +AX 2A 435MHz - 605MHz700.2MHz - 905.2MHz100KHz265.2MHz +BX 2A 605MHz - 825MHz905.2MHz - 1090.2MHz100KHz265.2MHz +CX 2A 825MHz - 1050MHz1090.2MHz - 1315.2MHz 100KHz265.2MHz +DX 2A 1050MHz - 1135MHz784.8MHz - 869.8MHz100KHz265.2MHz -BX 2A 1135MHz - 1355MHz869.8MHz - 1089.8MH

43、z100KHz265.2MHz -CX 2A 1355MHz - 1580MHz1089.8MHz - 1314.8MHz 100KHz265.2MHz -DX 2A 1580MHz - 1625MHz824.8MHz - 894.8MHz100KHz755.2MHz -BX 2B 1625MHz - 1845MHz894.8MHz - 1089.8MHz100KHz755.2MHz -CX 2B 1845MHz - 2075MHz1089.8MHz - 1319.8MHz 100KHz755.2MHz -DX 2B 2075MHz - 2155MHz1319.8MHz - 1399.8MHz

44、 200KHz755.2MHz -AX 4B 2155MHz - 2495MHz1399.8MHz - 1739.8MHz 200KHz755.2MHz -BX 4B 2495MHz - 2955MHz1739.8MHz - 2199.8MHz 200KHz755.2MHz -CX 4B 2955MHz - 3395MHz2199.8MHz - 2639.8MHz 200KHz755.2MHz -DX 4B 1st VCO A B C D A B O ? ? ? ? ? 290 P ! ?#$ ! ? ?% ! := 2 ?A 79:O ? ? ? ?B? ?C% ! I *J GLKM ,

45、DC VOLTAGESSR2K-IFCP IC104AD603IC110TA31137FN PIN No.DC (V)DC (V)PIN No.PIN No.DC (V)DC (V)PIN No. (1)1.24.9(8)(1)4.40.9(24) (2)0.60(7)(2)4.00(23) (3)0-5.0(6)(3)4.40.7(22) (4)00(5)(4)3.10.5(21) (5)4.40.3(20) IC105AD603(6)4.00(19) (7)4.00.7(18) PIN No.DC (V)DC (V)PIN No.(8)3.40.6(17) (1)0.64.9(8)(9)4

46、.40(16) (2)0.60(7)(10)4.01.1(15) (3)0-5.0(6)(11)4.04.4(14) (4)00(5)(12)03.5(13) IC107AD8307 IC111CXA1611N PIN No.DC (V)DC (V)PIN No. (1)3.23.2(8)PIN No.DC (V)DC (V)PIN No. (2)04.9(7)(1)04.5(24) (3)1.74.9(6)(2)3.74.5(23) (4)0.64.5(5)(3)0.53.7(22) (4)00.8(21) IC109uPC358G2(5)1.21.1(20) (6)1.31.5(19) P

47、IN No.DC (V)DC (V)PIN No.(7)2.10.9(18) (1)4.86.0(8)(8)1.50(17) (2)00(7)(9)00(16) (3)6.00(6)(10)00.4(15) (4)00(5)(11)00(14) (12)1.40.4(13) IC116uPC358G2 PIN No.DC (V)DC (V)PIN No.TR101 2SC4536 (1)2.55.0(8) (2)2.52.5(7)PIN No.DC (V) (3)2.52.5(6)B2.3 (4)02.5(5)C3.5 E1.5 IC117LA4425A PIN No.DC (V)TR105

48、2SK208 (1)1.4 (2)0PIN No.DC (V) (3)0G0 (4)4.9D2.4 (5)10.0S0.6 DC VOLTAGESSR2K-FRMX IC301RF2312 RX : 25 - 480MHzIC339AD8343 RX : 25 - 1696MHz PIN No.DC (V)DC (V)PIN No. PIN No.DC (V)DC (V)PIN No.(1)00(14) (4)00(5)(2)1.33.6(13) (3)00(6)(3)1.33.6(12) (2)00(7)(4)2.10(11) (1)3.06.4(8)(5)4.90.4(10) (6)00.4(9) (7)00(8) IC303 SGA-6489 RX : 480 - 1030MHz PIN No.DC (V)IC348AD8343 RX : 1696 - 3300MHz IN1.7 GND0PIN No.DC (V)DC (V)PIN No. OUT4.9(1)00(14) (2)1.23.7(13) (3)1.23.7(12) IC305 SGA-6489 RX : 1030 - 1696MHz(4)2.10(11) (5)4.80.4(10) PIN No.DC (V)(6)00.4(9) IN1.6(7)00(8) GND0 OUT4.8 IC357AD8343 RX