Sennheiser-EM100_EM300_EM500-rtf-sm2 电路图 维修手册.pdf

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1、SA 040818 Subject to alterations Sennheiser electronic GmbH -3dB Monitor output level/load _ 100mW/32 (only EM 500 G2) AF outputs _ (6.3mm) jack socket Unbalanced XLR-3M, balanced Pilot tone Pilot tone frequency _32.768kHz Pilot tone deviation _ 1.5kHz EM 100 G2, EM 300 G2, EM 500 G2 708/2004 3Descr

2、iption The receiver has a modular structure and comprises the following boards: Mainboard Display module RF module Monitor module (only EM 500 G2) The display, RF and monitor modules are each connected to the mainboard via a 15-pin ribbon connection. The following sections explain the principal func

3、tions. 3.1Mainboard The mainboard is a single-sided PCB assembly. It is manually screwed to the side walls, the front and the back panel wall and the RF module. The mainboard performs the following functions: Conditioning of power supply Conditioning of AF signals Provision of power supply to additi

4、onal modules Control of own functions and the RF and monitor module via the microprocessor 3.1.1Processing the diversity signal The signal from the RF module with the highest field strength is switched by the U50 or U51 diversity switches and reaches four signal conditioning blocks that are connecte

5、d in parallel. 3.1.2U52 squelch switch with AF conditioning If the squelch threshold you set is exceeded, U1 uses U52 to switch the AF signal and activates the AF high pass filter with U75-1, the AF low pass filter with U75-2 and U76-1, the HDX expander with U100 and the AF stages U101-1, U101-2 and

6、 U76-2. With EM 500 G2 the AF stages U101-1 and U101-2 are used via analog switch U300 as LOW-CUT filters with a threshold frequency of 200Hz and with U301 as HI-BOOST filters with an increase of approx. 5dB at 10kHz. Control is via U1, Q300-1 and Q300-2. The peak detector is connected to the level

7、indicator behind U76-1 with U100 ope- rational amplifiers (U100-2 and U100-1) whose output signal DEV_L is available to microprocessor U1 for evaluation. The two AF signals AF_0 (U76-2) and AF_180 (U101-2) both reach a divider resistance chain at the inputs of analog switches U175 and U176, via whic

8、h eight AF signal switching stages are set by the user. The structure is strictly balanced and is laid behind the active stages to guarantee full signal to noise ratio even if the AF signal is weakened by approx. 40dB. From the two outputs, the AF signal then reaches across various components to pro

9、tect from ESD parasitic signals and phantom voltage at AF sockets P175 and J175. EM 100 G2, EM 300 G2, EM 500 G2 08/20048/32 3.1.3Evaluation of the TX battery signal The battery telegram sent by the transmitter reaches the U60-2 trigger stage, at whose output appropriate square wave signals are avai

10、lable for evaluation by U1, via the 4Hz low pass filter with U60-1. 3.1.4Evaluation of the pilot signal The 32.768kHz pilot signal sent by the transmitter is filtered from the signal mix by the active crystal filter with Q95, Y95 and U95-1, rectified via the D95 diode and made available for evaluati

11、on by U1 via trigger stage U96-1. 3.1.5Functions of microprocessor U1 The receiver is controlled by the 8-bit U1 microprocessor, which contains in its flash memory the control program and uses a sub-area as an EEPROM for saving data even in the event of power failure. The microprocessor uses a 4MHz

12、crystal to generate both its own internal 8MHz cycle and the reference frequency for the RF module PLL. It processes the signals already described in line with the program specifications and the user specifications that can be set on an individual basis via a menu. 3.1.6Service interface (RJ45 socke

13、t) The service interface “DATA“ with RS485 protocol, located on the back panel of the unit, fulfills an important function. The RJ45 socket allows the relevant EEPROM pa- rameters on the RF module and the simulated EEPROM to be read out and modified in the microprocessor. This interface also enables

14、 a software update as part of the hardware options. For example, the RJ45 socket enables you to read unit data and write-in after replacing a board. The necessary service software is available for download free of charge on our Internet homepage: Service the following functions are performed by the

15、plug-in connection: Incoming power supply of 5V DC from the mainboard. Incoming system cycle (4MHz) from mainboard microprocessor. 2 x outgoing AF voltage to mainboard 2 x RSSI voltage to mainboard. Communication between the mainboard microprocessor and the EEPROM or the PLL for the RF module. EM 10

16、0 G2, EM 300 G2, EM 500 G2 908/2004 3.2.1RF module shielded compartments The shielded compartments on the RF module perform the following functions: The two compartments between the BNC sockets contain the second mixer, the 10.7MHz limiting amplifier and the FM demodulator. The compartment directly

17、behind the BNC socket contains RF conditioning up to an including the SAW filter for the first IF. The middle compartment performs frequency conditioning for the first oscillator with VCO, buffer and PLL for both diversity channels. The input filters are assembled outside the shielded compartments t

18、o ensure that parasitic LO frequency currents cannot be coupled directly to the RF input. The in- put filters are relatively complex owing to the integrated IF and LO cases, but nevertheless do not require alignment. 3.2.2Alignment of the RF module The only components still to be adjusted are C540 f

19、or alignment of VCO voltage at center frequency, C330 for setting the LO2 crystal oscillator, The L310 and L410 discriminator coils, and The two level adjusters for the AF outputs. For communication with the processor on the mainboard, the RF module contains the U700 EEPROM, in which the relevant fr

20、equency range data, the RSSI table and other status data are stored. Communication is processed via the same bus used by the microprocessor to communicate with the PLL U500 (frequency setting). 3.3Display module The display module for the status displays is connected to the mainboard via a 15-pin ri

21、bbon connection. 3.4Monitor module (only EM 500 G2) The monitor module (MOD.A020) is a single-sided PCB assembly and is connected to the mainboard via a 15-pin plug-in connector. The monitor module PCB has a jack socket for connecting headphones, and an appropriate volume control. The monitor module

22、 also has a complete U1 and U2 amplifier for each AF phase; the volume can be adjusted via R1. The monitor module is primarily intended for stereo operation, but in phase confi- guration is possible for mono operation. If you want to minimize the volume diffe- rences in mono operation between the le

23、ft and right channel (this may occur as a result of the tolerances of R1), you must close the M1 solder bridge. You must not close the M1 solder bridge if you are using the monitor module in stereo mode. EM 100 G2, EM 300 G2, EM 500 G2 08/200410/32 4Exploded view 4.1Exploded view: EM 100 G2 001 002

24、003 002 005 004 005 004 008 009 012 018 018 018 017 013 013 016 016 019 007 003 011 020 020 006* Pos. 006 incl.: 017 018 * EM 100 G2, EM 300 G2, EM 500 G2 11/3208/2004 4.2Exploded view: EM 300 G2, EM 500 G2 001 002 003 002 008 009 011 012 013 014 016 016 019 020 015 012 010 013 007 003 006* Pos. 006

25、 incl.: 017 018 * 005 004 005 004 020 017 018 EM 100 G2, EM 300 G2, EM 500 G2 08/200412/32 PosBezeichnung 001Casing 002Lens screw 003Holder 004Lens screw 005Spring washer 006Front module with display 007Rear panel 008Label 009PCB mainboard 010PCB monitoring module (EM 500 G2 only) 011PCB RF module 0

26、12Lens screw 013Flat cable, 15-pin 014Flat cable, 30-pin 015Knob (EM 500 G2 only) 016Socket BNC 50R 017Key cap ON/POWER 018Key cap UP/DOWN/SET 019Built-in plug XLR3M 020Lens screw EM 100 G2, EM 300 G2, EM 500 G2 13/3208/2004 5Test and alignment instructions 5.1Measuring and test equipment 1 Spectrum

27、 analyzer up to at least 1.5GHz 1 RF signal generator 1 AF level measuring device 1 Oscilloscope 1 Multimeter 1 Laboratory power supply unit 5.2Measuring set-up + 230.00 MHz DATA RF signal generator AF level measuring device Oscilloscope EM x00 G2EM x00 G2 Laboratory Spectrum analyzerMultimeter Othe

28、r measuring equipmentOther measuring equipment DC IN RF IN AF OUT power supply unit EM 100 G2, EM 300 G2, EM 500 G2 08/200414/32 5.3Test table SequenceType of measure- ment/adjustment Signal inputSettingsMeasuring point/test point Required value Remarks 1Visual inspection 1.1Jack socket PHONES (only

29、 EM 500 G2) Contacts are not twisted, no hairline cracks at the solder points, no mechanical damage 1.2Volume control (only EM 500 G2) See 1.1 1.3?, SET, POWER/ON buttons See 1.1 1.4DC socket, DC INSee 1.1 1.5XLR socketSee 1.1 1.6Jack socketSee 1.1 1.7RJ45 DATA socketSee 1.1 1.8BNC socketsSee 1.1 1.

30、9Monitoring of all display elements +12VDC at DC socketPOWER = ONMonitoring of all display segments 1.10Monitoring of the il- luminated ?, SET, ON buttons (not EM 100 G2) See 1.9See 1.9 2Mainboard: current and voltage measurement 2.1StandbySee 1.9POWER = Off VOL = min. (R1) AF level = max. 50mASet l

31、aboratory power supply unit current limiter to ION = 1A 2.2Current consumpti- on during operation See 1.9POWER = On VOL = min. (R1) AF level = max. 200mASee 2.1 2.3CommissioningSee 1.9VOL = min. (R1) AF LEVEL = max. 2.4Operating voltage (+12VDC) See 1.9POWER = OnMainboard, solder side: TP209 (+) TP2

32、08 (-) +12VDC 2.5Operating voltage (+6VDD) See 1.9See 2.4TP226/ GND+5.8V to +6.2V 2.6Operating voltage (+5VCC) See 1.9See 2.4TP231/ GND+4.8V to +5.2V 2.7Operating voltage (+5VSW) See 1.9See 2.4TP233/ GND+4.8V to +5.2V 2.8Operating voltage (+6VSW) See 1.9See 2.4TP229/ GND+5.8V to +6.2V EM 100 G2, EM

33、300 G2, EM 500 G2 15/3208/2004 3RF module RF module removal: 1. Loosen the lens screw (RF board fastening, see Exploded view, Pos. 12). 2. Remove both BNC socket screws from the back panel of the unit. 3. Remove the RF module (the connection to the mainboard via the 15-pin flat cable remains). Re-es

34、tablishing the ground connection between the RF module and the mainboard: Create an interference-free connection between MH3 on the RF board and 801 on the mainboard. To do this, solder a wire approx. 10cm long between MH3 and 801. 3.1Operating voltage (+5VSW) +12VDC at the DC socket Multimeter, DCR

35、F module Component side: L500 +4.9V to +5.1V 3.2Tuning voltage measurement 1. Open the center shielded compartment on the RF module. 2. On the track, solder a piece of wire approx. 2cm long to TP17 and one to TP4. 3. Guide the wires out of the receiver as measuring lines. 4. Set the C540 trimmer in

36、the shielded compartment to precisely 2.4V; (use TP17 and TP4 for this). 3.2.1Mid range limit See 3.1Use TUNE to set the medi- um receiving frequency. RF module Solder side: TP 17 +2.3V to +2.5V Alignment via RF module, component side C540 3.2.2Lowest range limit See 3.1Use TUNE to set the lowest re

37、ceiving frequency. TP 17+0.8V to +2.0V 3.2.3Uppermost range limit See 3.1Use TUNE to set the highest receiving frequency. TP 17+3.0V to +4.2V 3.3Oscillator 3.3.11. frequency measurement See 3.1Use the SET and DOWN buttons to switch to the mid receiving frequency; then spectrum analyzer TP 1LO1= fE +

38、241MHz 3.3.21. Oscillator levelSee 3.1See 3.3.1TP 102 / TP 202 +4.3 VMeasurement takes place in- directly via the voltage at the 1st oscillator 3.3.32. frequency measurement See 3.1See 3.3.1TP 300230.3MHz 11.5kHz 3.3.42. Oscillator levelSee 3.1See 3.3.1TP 300-20dBm to -35dBm 3.4Sensitivity, channel

39、1 Set the receiving fre- quency on the RF signal generator: ANT I RF: 2, 5V; devia- tion: 24kHz mod: off Center frequency; Squelch at 0; AF level measuring device AF outputBetter than 52dB(A) 3.5Sensitivity, channel 2 See 3.4 at ANT IISee 3.4AF outputBetter than 52dB(A) 3.6THD, channel 1RF signal ge

40、nerator at ANT I RF: 1mV; deviati- on: 24kHz mod: 1kHz AF output 0.9%, typ. 0,3% 3.7THD, channel 2See 3.4 at ANT IIAF output Service & Distributors Service Documentation Download The minimum operating system requirement to run the software is Microsoft Windows 95 , and a free COM port (RS232) is als

41、o required. 5.4.4Information about the service software A user guide for the service software is available in PDF format. It contains information about how to commission the service set, how to install the service software and how to read in/out unit data. Please find more informations in the instru

42、ctions for use of the ew G2 service software. Once the installation of the software is complete you can find this help file in the Windows menu Start. EM 100 G2, EM 300 G2, EM 500 G2 08/200418/32 5.4.5Commissioning after board replacement After you have fitted a new board to the unit, you must use t

43、he service software to write the data to the unit again (e.g. new frequency table). RequirementsRequirements 1. You have replaced a faulty board (e.g. receiver RF board), 2. You have connected the receiver via the DC IN an +12 V DC socket. 3. You have connected the unit to the COM port on the PC via

44、 the “DATA“ service interface. 4. You have installed the service software and launched it. 5. You have switched on the unit. Writing unit dataWriting unit data Perform the following steps: 1. Click the button Auto Detect. Result: Your connected unit is detected. 2. Click the button EXECUTE ALL in th

45、e Info tab. Result: All unit data is read out. If all the data are successfully read out, the message “Success“ appears. Note: If you perform individual actions in the “Info“ or “Service“ tabs, you must subsequently return the unit to operational status. Click on Close Device once the actions have b

46、een completed to do this. 3. Switch to the “Service“ tab. 4. Click the button EXECUTE ALL. Result: The new unit data will be written. If all the data are successfully written, the message Success appears. Result Result You have successfully written the new data to the unit. These new data now corres

47、pond to the new factory settings for your unit. Your can find these data in “D:Sennheiserew G2 service package“ in the files “Defaults.dat“ and “FreqTable.dat“ or alternatively “FreqTableIEM.dat“. EM 100 G2, EM 300 G2, EM 500 G2 19/3208/2004 6Circuit diagrams ON/OFF SELECT DOWN UP +5V +5Vsw +6Vsw +1

48、0-15V/50mA DATA/CLK 100mw max +10dBu max - + -22.+18dBu LEVEL_MON AF-ON HDX EXP TX_BATT DETECTOR 25KHz 30Hz 5Hz MUTEDIVERSITY LP_100KHz DISCR.LIM.AMP LIM.AMP 10.7MHz10.7MHzMIXER241MHzMIXER BPF 230.3MHz LP_100KHzDISCR. LIM.AMPLIM.AMP10.7MHz10.7MHz 230.3MHz f_IN 241MHz MIXER241MHzMIXERBPF EE-EPROM 10.

49、5-16VDC IN AF-2 AF-1 AF-1 RF-2 RF-1 MONITOR-MODUL EM500 ONLY AF-OUT BALANCED LCD SUPPLY UNIT MAIN uC - + - + - + 300903Prl1530 PLLVCO MCK 4MHz MCK = Main clock MCK 4MHz PILOT DETECTOR 32.768kHz -6Vsw -7Vsw MAIN-BOARD AF-2 FRONTMODUL -AF +AF +8Vsw DATA U100Y100U300Y302Q304 Q504 Q506U500 U200Y200U400Y402Q404Y404U400U400 U700 R460U402 R360U302 RF-BOARD Y304Q300 U300 U75 U75 U76 U100R79U52 U60U60 U50 U51 U95 U96 U225 U210 U226 U227 U1 U101 U76U175 U176 R1 U2 (EM550 from Splitter 1) (EM550 from