ORBAN 2200 Manual Section 4 电路图.pdf

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1、Section 4 Maintenance pagecontents 4-2Routine Maintenance 4-3Getting Inside the Chassis 4-7In-System Testing (“Proof of Performance”) 4-8Monophonic Performance Verification 4-10Stereo Performance Verification 4-16Field Audit of Performance 4-18Test Power Supplies (optional) 4-22Test Stereo Baseband

2、Encoder 4-26Figure 4-1: Separation Scope Trace 4-27Field Alignment 4-28Prepare the Unit 4-28System Default Settings 4-29Calibrate and Test Analog Input/Output Circuitry 4-29Return OPTIMOD-FM to Service CAUTION The installation and servicing instructions in this manual are for use by qualified person

3、nel only. To avoid electric shock do not perform any servicing other than that contained in the Operating Instructions unless you are qualified to do so. Refer all servicing to qualified service personnel. OPTIMOD-FM 2200MAINTENANCE 4-1 RadioFans.CN 收音机爱 好者资料库 page Routine Maintenance The 2200 OPTIM

4、OD-FM Audio Processor uses highly stable analog and digital circuitry throughout. Recommended routine maintenance is minimal. 1. Periodically check audio level and gain reduction meter readings. Become familiar with normal audio level meter readings, and with the normal perform- ance of the G/R mete

5、ring. If any meter reading is abnormal, see Section 5 for trou- bleshooting information. 2. Listen to the 2200s output. A good ear will pick up many faults. Familiarize yourself with the “sound” of the 2200 as you have set it up, and be sensitive to changes or deteriorations. But if problems arise,

6、please dont jump to the conclusion that the 2200 is at fault. The troubleshooting information in Section 5 will help you determine if the problem is with OPTIMOD-FM or is somewhere else in the stations equipment. 3. Periodically check for corrosion. Particularly in humid or salt-spray environments,

7、check for corrosion at the input and output connectors and at those places where the 2200 chassis contacts the rack. 4. Periodically check for loss of grounding. Check for loss of grounding due to corrosion or loosening of rack mounting screws. 5. Clean the front panel when it gets soiled. Wash the

8、front panel with a mild household detergent and a damp cloth. Stronger solvents should not be used because they may damage plastic parts, paint, or the silk-screened lettering (99% isopropyl alcohol can be safely used). 4-2 MAINTENANCE OPTIMOD-FM 2200 RadioFans.CN 收音机爱 好者资料库 Getting Inside the Chass

9、is 1. Removing the Top Cover. To access the main board, power supply board or display assembly, you must remove the top cover. ADisconnect the 2200 and remove it from the rack. Be sure power is disconnected before removing the cover. WARNING: Hazardous voltage is exposed with the unit open and the p

10、ower ON. BSet the unit upright on a padded surface with the front panel facing you. CRemove all twenty screws holding the top cover in place, and lift the top cover off. Use a #1 Phillips screwdriver. 2. Removing the Display Assembly. Note: You will need to complete this step if you intend to remove

11、 the main board. AGently pull off the front panel control knob. BRemove backlight power connector CDetach the four ribbon cables that connect the display board to the main board and power supply board. a)First, identify the four cables: A larger white flat cable connecting to jumper J200 on the main

12、 board; A gray ribbon cable connecting to a DIP header at jumper J203 on the main board. A smaller white flat cable connecting the display assembly to the power supply at jumper J202. A two-wire cable connecting the display assembly to the power supply at jumper J201. b)Gently lift each cable up fro

13、m where it connects to its jumper, so that the jumper pins unseat without bending or breaking. (If present, you must first remove the retainer clip from the DIP header at J203.) DRemove the four nuts that connect the display board to the main chassis. Use a 14“ long shafted nut driver or a flexible

14、shaft nut driver. EGrasp the edges of the front panel, pull slightly forward, and, while holding the panel vertical, guide it forward. OPTIMOD-FM 2200MAINTENANCE 4-3 RadioFans.CN 收音机爱 好者资料库 3. Removing the Main Board. AIf you have not done so yet, remove the top cover (Step 1) and remove the display

15、 assembly (Step 2). BRemove the display boards metal shielding; this was left in place when the display board was detached. CRemove the two hex nuts holding each composite output connector to the chassis, using a 316“ hex nut driver. DRemove the two hex nuts holding the Remote Interface connector to

16、 the chassis, using a 316“ hex nut driver. EDetach all 4 XLR connectors (or 6 with Model 2200-D), using a jewelers screw- driver; engage the locking mechanism and turn counterclockwise until the XLR is no longer attached. FRemove the two ribbon cables that connect the power supply to the main board

17、at jumpers J900 and J901. (If present, you must first remove the black retainer clips.) GRemove the four #1 Phillips screws that connect the main board to the chassis. HCarefully pull the main board forward to clear XLRs from their housing and then out of the chassis. 4. Removing the Power Supply Bo

18、ard. AIf you have not done so yet, remove the top cover (Step 1). BIf you have not done so yet, remove the ribbon cables that connect the display assembly to the power supply board (at jumpers J201 and J202), as well as the two cables that connect the main board to the power supply (at jumpers J900

19、and J901). CRemove the twelve #1 Phillips screws holding the heat sink to the side of the chassis note that some have nuts and some are tapped and remove heat sink. DRemove the two Phillips screws that hold the IEC connector to the chassis. ERemove the four bolts that hold the transformer; retain th

20、e four star washers and eight plastic insulators. FRemove the three Phillips screws holding the power supply board to the main chassis. GRemove the nut and star washer from the ground wire with a 14“ nut driver. HCarefully lift the power supply board up. 4-4 MAINTENANCE OPTIMOD-FM 2200 5. Reattachin

21、g the Power Supply Board. AReplace the two Phillips screws that hold the IEC connector. BReplace the twelve #1 Phillips screws that hold the heat sink to the side of the chassis. CSet power supply board into main chassis, so that it aligns with its mounting holes. DReplace the ground wire nut. ERepl

22、ace the three Phillips screws that hold the power supply board to the main chassis. FReplace the four bolts that hold the transformer; use the starwashers and plastic insulators. GIf the main board is installed, reattach the two ribbon cables that connect the main board to the power supply. 6. Repla

23、cing the Main Board. ASet the main board into the main chassis, so that it aligns with its mounting holes. BReattach all 4 XLR connectors (or 6 with Model 2200-D), using a jewelers screwdriver. CReplace the two hex nuts that hold the Remote Interface connector to the chassis, using a 316“ hex nut dr

24、iver. DReplace the two hex nuts that hold each Composite Output connector to the chassis, using a 916“ hex nut driver. EReplace the four #1 Phillips screws that connect the main board to the chassis. FIf the power supply board is installed, reattach the two ribbon cables that connect the main board

25、to the power supply. OPTIMOD-FM 2200MAINTENANCE 4-5 7. Replacing the Display Board. AReattach the display boards metal shielding to the main chassis. BSet the display assembly in place so that it aligns with its mounting holes. CReplace the four nuts that connect the display board to the main chassi

26、s. Use a 14“ long shafted nut driver or a flexible shaft nut driver. DReplace the four ribbon cables that connect the display board to the main board and power supply board. EReplace the front panel control knob. 8. Replacing the Top Cover. APlace top on unit and reattach the twenty Phillips screws.

27、 (Be careful not to pinch the ribbon cables or the two-wire backlight power connector.) 4-6 MAINTENANCE OPTIMOD-FM 2200 In-System Testing (“Proof of Performance”) The FCC (Federal Communications Commission U.S.A.) no longer requires periodic Proof of Performance measurements for FM stations. However

28、, many stations will still wish to make periodic equipment performance measurements to ensure that their transmission system is working correctly and that they comply with all government regulations. The text below provides the general information that is needed to perform measurements verifying the

29、 performance of a transmission system including the 2200. Instructions for bench-top verification of 2200 performance outside of the transmission system are found below in Field Audit of Performance starting on page 4-16. These instructions are written with the assumption that the analog inputs and

30、outputs are used. If the 2200-Ds digital I/O is used instead, follow the procedures below by analogy you will have to supply digitized test tones. The NAB Broadcast and Audio System Test CD provides a good source of digitally- generated test tones on compact disc. They supply tones at a 44.1kHz samp

31、ling rate that can be applied to the 2200-Ds AES/EBU input. This test CD is available from: NAB Services 1771 N Street N.W. Washington, D.C. 20036, U.S.A. order: (1) (800) 368-5644 Required Equipment: Ultra-low distortion sine-wave oscillator/THD analyzer/audio voltmeter (With verified residual dist

32、ortion below 0.01%. Sound Technology 1710B; Audio Precision System One, or similar high-performance system.) (The NAB Broadcast and Audio System Test CD is an excellent source of test signals when used with a high-quality CD player.) Precision FM modulation monitor or demodulator (Belar FMMA-1; TFT

33、844, or similar.) Precision stereo monitor or demodulator (Belar FMSA-1; TFT 844, or similar.) optionally, baseband spectrum analyzer, 0-100kHz (Tektronix 5L4N plug-in with 5111 bistable storage mainframe or similar.) OPTIMOD-FM 2200MAINTENANCE 4-7 Monophonic Performance Verification Monophonic perf

34、ormance verification is straightforward. Begin with the 2200 in stereo Mode, recall Bypass Test preset, and drive the Left OPTIMOD-FM Analog Input with the test signal. 1. Prepare the unit. AUse the front panel controls to set the 2200s software controls to their default settings, as follows: Preset

35、 2B GENERAL PURPOSE I/O CALIB (ANLG INP CALIB) INPUTanalog AI REF VU+4.0dBu AI REF PPM+12.0dBu AI CLIP+20.0dBu I/O CALIB (DIG INP CALIB); 2200-D only INPUTanalog DIG STATno lock (depends if digital signal is present DI REF VU30.0dBFS DI REF PPM22.0dBFS IO CALIB (ANLG OUTP CALIB) AO 100%+10.0dBu AO P

36、RE-Eflat IO CALIB (DIG OUTP CALIB); 2200-D only DO 100%2.8dBFS DO PRE-Eflat DO RATE32kHz DO SYNCinternal STEREO ENCODER PROC PRE-E50s or 75s, as appropriate to your country MODEstereo PILOTLVL9.0% XTLK TESTnormal TEST MODEoperate TONE400Hz BYPASS GAIN0dB BPress System Setup button to access System S

37、etup menu. CPress TEST soft key to access Test menu. DRecall TONE preset: Press MODE soft key, use the control knob to scroll to tone, then release the MODE soft key. EAdjust COMPOSITE 1 OUTPUT or COMPOSITE 2 OUTPUT for a reading of 100% on the modulation meter. 4-8 MAINTENANCE OPTIMOD-FM 2200 FPres

38、s System Setup button to re-access System Setup menu. GPress TEST soft key to access Test menu. HRecall bypass preset: Press MODE soft key, use the control knob to scroll to bypass, then release the MODE soft key. Bypass defeats all compression, limiting, and clipping, but leaves the 15kHz low-pass

39、filter in the signal path. IInject both channels of the 2200 with a 50Hz signal, and adjust the signal generators output level to obtain 100% composite modulation. (This level is the reference level.) JInject Left Channel at 50Hz with the reference level input (as established in the previous step).

40、Drive the left channel with the reference level input and ground the right channel (by tying pins #2 and #3 together). KPress System Setup button to re-access System Setup menu. LPress STEREO ENCODER soft key to access Stereo Encoder menu. MSet 2200 for mono-L operation: Press MODE soft key, use the

41、 control knob to scroll to mono-L, then release the MODE soft key. NVerify 100% modulation level on the left and right modulation meters. OSet 2200 for mono-R operation: Press MODE soft key, use the control knob to scroll to mono-R, then release the MODE soft key. PVerify no level on modulation mete

42、rs. QInject Right Channel at 50Hz with the reference level input (as established in the previous step). Drive the right channel with the reference level input and ground the left channel (by tying pins #2 and #3 together). RPress System Setup button to re-access System Setup menu. SPress STEREO ENCO

43、DER soft key to access Stereo Encoder menu. TSet 2200 for mono-R operation: Press MODE soft key, use the control knob to scroll to mono-R, then release the MODE soft key. UVerify 100% modulation level on the left and right modulation meters. VSet 2200 for mono-L operation: Press MODE soft key, use t

44、he control knob to scroll to mono-L, then release the MODE soft key. WVerify no level on modulation meters. OPTIMOD-FM 2200MAINTENANCE 4-9 Stereo Performance Verification Many stations may wish to verify that they meet the requirements of the old part 73.322 of the FCC Rules (which was deleted in 19

45、83, and which referred to stereo performance). Part 73.322 referred to the performance of the transmitter only (starting with stereo encoder input terminals), and measurements may be made by connecting the test oscillator directly to the OPTIMOD-FM main audio inputs. Following is an outline of the a

46、ppropriate measurements and how to perform them. 1. Prepare the unit. AUse the front panel controls to set the 2200s software controls to their default settings, as follows: Preset 2B GENERAL PURPOSE I/O CALIB (ANLG INP CALIB) INPUTanalog AI REF VU+4.0dBu AI REF PPM+12.0dBu AI CLIP+20.0dBu I/O CALIB

47、 (DIG INP CALIB); 2200-D only INPUTanalog DIG STATno lock (depends if digital signal is present) DI REF VU30.0dBFS DI REF PPM22.0dBFS IO CALIB (ANLG OUTP CALIB) AO 100%+10.0dBu AO PRE-Eflat IO CALIB (DIG OUTP CALIB); 2200-D only DO 100%2.8dBFS DO PRE-Eflat DO RATE32kHz DO SYNCinternal STEREO ENCODER

48、 PROC PRE-E50s or 75s, as appropriate to your country MODEstereo PILOTLVL9.0% XTLK TESTnormal TEST MODEoperate TONE400Hz BYPASS GAIN0dB BPress System Setup button to access System Setup menu. CPress TEST soft key to access Test menu. 4-10 MAINTENANCE OPTIMOD-FM 2200 DRecall TONE preset: Press MODE s

49、oft key, use the control knob to scroll to tone, then release the MODE soft key. EAdjust COMPOSITE 1 OUTPUT or COMPOSITE 2 OUTPUT for a reading of 100% on the modulation meters. FPress System Setup button to re-access System Setup menu. GPress TEST soft key to access Test menu. HRecall bypass preset: Press MODE soft key, use the control knob to scroll to bypass, then release the MODE soft key. Bypass defeats all compression, limiting, and clipping, but leaves the 15kHz low-pass filter in the signal path. IInject both channels of the 2200 with a 50Hz signal, and adjust its outp