Kenwood VT-185_VT-186_VT-187_1 电路图.pdf

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1、VT-187 only FRONT PANEL VT-185: (A63-0303-08) VT-186: (A63-0304-08) VT-187: (A63-0305-08) SIDE PANEL (A13-2254-08) PUSH KNOB (K24-3015-08) HANDLE: (K01-0564-08) HANDLE COVER : (B09-0410-08) ROTARY KNOB (K21-0960-08) RUBBER FOOT (J02-0543-08) 2CH AC VOLTMETER VT-185/VT-186/VT-187 SERVICE MANUAL KENWO

2、OD TMI CORPORATION 1998-8/B51-1134-00 (K/K) VT185(K)internet 98.7.30 15:29 y W 2 RadioFans.CN 收音机爱 好者资料库 VT-185/VT-186/VT-187 2 The following instructions are for use by qualified personnel only. To avoid electric shock, do not perform any servicing other than contained in the operating instructions

3、 unless you are qualified to do so. WARNING CONTENTS SPECIFICATIONS .3 SAFETY .4 CIRCUIT DESCRIPTION.5 BLOCK DIAGRAM .6 ADJUSTMENT.7 PARTS LIST (UNIT).10 PARTS LIST (ELECTRICAL).11 SCHEMATIC DIAGRAM .16 P.C. BOARD .26 VT185(K)internet 98.7.30 15:29 y W 3 RadioFans.CN 收音机爱 好者资料库 Gain Output voltage O

4、utput resistance Distortion Signal to noise ratio Frequency response ITEMS Meter Section VT-185 Amplifier Section VT-186VT-187 Measurable voltage dB dBm Error Frequency response Input impedance Max. input voltage Stability Residual Voltage Crosstalk Individual Crosstolk Interlock 1mV to 300mV in ran

5、ges: 1, 3, 10, 30, 100, 300mV, 1 , 3, 10, 30, 100, 300V full scal. 0.3mV to 100mV in 12 ranges : 0.3, 1, 3, 10, 30, 100, 300mV, 1, 3, 10, 30, 100V full scale. -80 to +50dB (0dB=1V)-90 to +40dB (0dB=1V) -80 to +52dBm (0dBm=1mW at 600) -90 to +42dBm (0dBm=1mW at 600) Within 3% of full scale at 1kHz 10

6、% at 5Hz to 1MHz, 5% at 10Hz to 500kHz, 3% at 20Hz to 200kHz and 2% at 30Hz to 100kHz as response to 1KHz response. 10M 5%, with less than 45pF parallel capacitance. 500V(DC +AC peak) 1V to 300V range 100V(DC +AC peak) 1mV to 300mV range 500V(DC +AC peak) 1V to 100V range 100V(DC +AC peak) 0.3mV to

7、300mV range Within 0.5% of full scale for 10% line voltage fluctuation Less than 20 V with input shorted on 1mV range Less than 30 V with input shorted on 0.3mV range Less than -50dB with other input terminated with 600 Less than -80dB with other input terminated with 600 Approx. 60dBApprox. 70dB 1V

8、rms (full scale) 20% 600 20% at 1kHz Less than 1% at full scale (Rated by signal to noise ratio in 0.3mV, 1mV and 1V range). Less than 1% at full scale (Rated by signal noise ratio in 1mV and 1V ranges) Over 40dB at full scale. (Over 30dB at 0.3mV range) Within 3dB at 5Hz to 500kHz Line voltage Powe

9、r consumption Dimensions W X H X D (mm) Environmental Power Supply Section Coefficient Temperature Relative humidity Maximum altitude Overvoltage Category Pollution Degree : 0.08%/C Within specifications :10 to 40C Full operation:0 to 50C Less than 80% 2000m 2 100/120/220/230 Vac 10% 50/60Hz Max. 11

10、W 128 (128) X 190 (210) X 239 (269) Value in ( ) include protrusions Approx. 3.2 kgApprox. 3.1 kgNet Weight 1 pc. CA-41p 2 pcs. 1 pc. 1 copy 1 pc. EN55011 (1991) CLASS B IEC801-2 (1991) 8kVAD IEC801-3 (1984) 3V/M IEC801-4 (1988) Accessories Power cable Input cable Replacement fuse Instruction manual

11、 Adjust driver Regulatory Information (VT-186 only) EMI Immunity 7 The above specifications are subject to charge without noise. VT-185/VT-186/VT-187 3 SPECIFICATIONS VT185(K)internet 98.7.30 15:31 y W 6 RadioFans.CN 收音机爱 好者资料库 VT-185/VT-186/VT-187 4 SAFETY SAFETY Before connecting the instrument to

12、 a power source, care- fully read the following information, then verify that the proper power cord is used and the proper line fuse is installed for power source. The specified voltage is shown on the rear panel. If the power cord is not applied for specified voltage, there is always a certain amou

13、nt of dan- ger of electric shock. Line voltage This instrument operates using ac-power input voltages that 100/120/220/230 V at frequencies from 50 Hz to 60Hz. Power cord The ground wire of the 3-wire AC power plug places the chassis and housing of the instrument at earth ground. Do not attempt to d

14、efeat the ground wire connection or float the instrument ; to do so may pose a great safety hazard. The appropriate power cord is supplied as an option that is specified when the instrument is ordered. The optional power cords are shown as follows in Fig.1 Line fuse The fuse holder is located on the

15、 rear panel and contains the line fuse. Verify that the proper fuse is installed by replacing the line fuse. Voltage conversion This instrument can be operated from 100 to 230V, 50/60Hz power source. Use the following procedure to change from 100 to 230V operation or vice versa. 1. Remove the fuse h

16、older. 2. Replace fuse F1 with a fuse of appropriate value. 3. Reinsert it for appropriate voltage range. 4. When performing the reinsertion of fuse holder for the voltage conversion, the appropriate power cord should be used. (See fig.1) North American 120 volt/60 Hz Rated 15 amp (12 amp max ; NEC)

17、 Universal Europe 230 volt/50 Hz Rated 16 amp U.K. 230 volt/50 Hz Rated 5 amp Australian 240 volt/50 Hz Rated 10 amp North American 240 volt/60 Hz Rated 15 amp (12 amp max ; NEC) Switzerland 230 volt/50Hz Rated 10 amp Fig.1 Power Input Voltage Configuration Plug configurationpower cord and plug type

18、 Factory installed instrument fuse 0.2A, 250V slow blow 5x20mm 0.1A, 250V slow blow 5x20 mm 0.1A, 250V slow blow 5x20 mm 0.1A, 250V slow blow 5x20 mm 0.2A, 250V slow blow 5x20mm 0.3A, 250V slow blow 5x20 mm Line cord plug fuse None None None Parts No. for power cord E30-1982-08 E30-1985-08 E30-1986-

19、08 None 5A Type C None E30-1983-08 VT185(K)internet 98.7.30 15:31 y W 7 General A Signal voltage to be measured, which is input from the INPUT connector, is passed through the First Attenuator and is converted to a low impedance by the Impedance Convertor. The impedance-converted signal is normalize

20、d, or further attenuated in proportion to 1mVrms fullscale value through the Second and Third Attenuator. The normalized signal is magnified 20-fold by the Main Amplifier and is fed to the Output Amplifier and the Absolute-Mean Value Detec- tor. The Output Amplifier magnifies the signal 50-fold and

21、feeds to the OUTPUT connector. The Absolute-Mean Value Detector converts the signal from the Main Amplifier to DC current in proportion to the absolute mean value. The con- verted signal activates the Meter. The Attenuator Control encodes the signal led from the RANGE selector to generate an Attenua

22、tor Control signal. This signal controls the First, Second and Third Attenuator to set the sensitivity corresponding to each range. The Power Supply feeds to the functional circuit 5V DC voltages stabilized by its IC regulator. Description of Functional Circuit 1) First Attenuator A potential divide

23、r acts as an attenuator. The amount of attenuation is switched in two steps by relay contacts:0dB and -60dB. 2) Impedance Converter A FET differential input Amplifier acts as an impedance con- verter with 0dB(10dB) gain, which converts the First Attenu- ator output signal to a sufficiently low imped

24、ance and feeds of the Second Attenuator. 3) Second Attenuator A resistance divider acts as an attenuator. The amount of attenuation is switch in two steps by relay contacts:0dB and -30dB. 4) Third Attenuator A resistance divider network acts as an attenuator. The amount of attenuation is switched in

25、 four steps by FET switch:0dB, -10dB, -20dB, and -30dB. 5) Main Amplifier A wideband, non-inverting differential amplifier acts as a main amplifier, which has high input impedance, low output impedance and 20-fold gain. This output signal level is 20mVrms for the fullscale read on the Meter. 6) Outp

26、ut Amplifier A wideband, non-inverting differential amplifier acts as an output amplifier, which has 50-fold gain and 600 output impedance. The output signal level is 1Vrms for fullscale read on the Meter, and works stable even for capacitive loads. 7) Absolute-Mean Value Detector An absolute-mean v

27、alue detector comprised of a high through-rate and high gain amplifier, which has very good linearity by negative feedback from the current flowing through the Meter load. In switching, this provides a suffi- ciently wide frequency band so that the high frequency phase compensation circuit is reset.

28、 8) Attenuator Control A logic control circuit comprised of a diode matrix and output buffer transistors. This encodes a 12-bit signal from the RANGE selector switch to 6-bit signals, which control the First, Second and Third Attenuator. The remote control con- nector is connected to this circuit. 9

29、) Power Supply The power source circuit supply 5V DC from the AC input, which contain a silicon diode bridge for full-wave rectifica- tion, high-capacitance electrolytic capacitors for smoothing, and an IC regulator stabilization. 10) CH1/CH2 Rotary Switch A 12-contact rotary switch for setting a de

30、sired channel 1 and 2 measurable voltage range. This feeds a signal corre- sponding to the range into the Attenuator Control. 11) CH2 Rotary Switch A 12-contact rotary switch for setting a desired channel 2 measurable voltage range. This feeds a signal correspond- ing to the range into the Attenuato

31、r Control. 12) CH2 Selector Switch A Selector which is used to select either individual or inter- locked range setting of channels 1 and 2. 13) CH1/CH2 Select Circuit The range setting individual or interlocked selection circuit are control by IC. 14) GND MODE Switch A switch is used to disconnect t

32、he input negative circuits from the casing ground. 15) Power ON/OFF The power switch is designed to act on the secondary side of the power transformer. The voltage or sentence in parenthes is applicable in case of the VT-185. In studying the operation of each circuit in voltmeter please refer to BLO

33、CK DIAGRAM. VT-185/VT-186/VT-187 5 CIRCUIT DESCRIPTION VT185(K)internet 98.7.30 15:31 y W 10 1st ATT GND OPEN GND MODE POWER TRANSFORMER POWER ON/OFF AC 100V/120V 220V/230V 50/60Hz GND INPUT-1OUTPUT-1 2nd ATT3rd ATT +5V VT-187 ONLY VT-187 ONLY ROTARY SW MAIN AMP OP-6RT-62 ABSOLUTE MEAN VALUE DET IMP

34、EDANCE CONVERTER ATT CONTROL OUTPUT AMP INPUT-2 INPUT-2 +5V CH1/CH2 SELECT CIRCUIT CH2 ROTARY SW CH2 SELECTOR +5V CH1/CH2 ROTARY SW VT-185/VT-186/VT-187 6 BLOCK DIAGRAM VT185(K)internet 98.7.30 15:31 y W 11 VT-185/VT-186/VT-187 7 ADJUSTMENT To obtain the best performance, periodically calibrate the

35、unit. Sometimes, only one mode need to be calibrated, while at other times, all modes should be calibrated. When one mode is calibrated, it must be noted that the other modes may be affected. When calibrating all modes, perform the calibration in the specified sequence. The following calibration req

36、uires an accurate measuring instrument and an insulated adjusting flat blade screwdriver. If they are not available, contact your dealer. For optimum adjustment, turn the power on and warm up the scope suffi- ciently (more than 30 minutes) before starting. Before calibrating the unit, check the powe

37、r supply voltage. TEST EQUIPMENT REQUIRED The following instrument or their equivalent should be used for making adjustment. PREPARATION FOR ADJUSTMENT Control Settings The control settings listed below must be used for each adjustment procedure. Exceptions to these settings will be noted as they oc

38、cur. After completing a adjustment, return the controls to the fol- lowing settings. Test Equipment Digital Multimeter Frequency Counter Oscilloscope Calibrator CR Oscillator Attenuator Q-Meter Distortion Meter Insulation Meter 50 Termination Model DL-712 FC-756 CS-6010 5100B AG-203 RA-920 4343B 885

39、 SM-5 TA-57 Maker KENWOOD KENWOOD KENWOOD FLUKE KENWOOD KENWOOD YHP Shibasoku TOA KENWOOD NAME OF KNOBS RANGE GND MODE CH2 SELECTOR POSITION VT-185 : 300V VT-186 : 100V VT-187 : 100V GND OFF VT185(K)internet 98.7.30 15:31 y W 14 VT-185/VT-186/VT-187 8 ADJUSTMENT 300mV rangeVR102 (Unless otherwise sp

40、ecified, the above connection should be used as to the follow- ing items.) CH1/2 SWITCH: 300mV (VT-185) 0.3V(VT-186/VT-187) CH2 SWITCH: 300mV (VT-185) 0.3V(VT-186/VT-187) CH2 SELECTOR: OFF 1) Input 1 kHz (or 400 Hz), 300 mVrms sine wave, and set the pointer to 3.0 of the 0-3 scale. Check that the va

41、riable range is less than 98% and more than 102% with respect to 3.0 (full-scale). 2) Waveforms shown on the oscilloscope shall not be deformed. 1V rangeVR101 CH1/2 SWITCH: 1V CH2 SWITCH: 1V CH2 SELECTOR: OFF 1) Input 1kHz (or 400 Hz), 1 Vrms sine wave, and set the pointer to 10.0 V of the 0- 10 sca

42、le. Check that the variable range is less than 98% and more than 102% with respect to 10.0 (full-scale). 2) Check that the operating, when CH2 SELECTOR is switched ON ( ) . 3) Waveforms shown on the oscilloscope shall not be deformed. ITEMPROCEDUREADJUSTMENT POINT Oscilloscope 50 oscillator Main uni

43、t REAR PANEL OUT PUT Oscillator or calibrator OscillatorCalibrator OKNGNG OUTOUT VT185(K)internet 98.7.30 15:31 y W 15 VT-185/VT-186/VT-187 9 ADJUSTMENT ITEM 100 kHz TC101 frequency CH1/2 SWITCH: 1V characteristicsCH2 SWITCH: 1V CH2 SELECTOR: OFF 1) Input a 1kHz (or 400 Hz), 1 Vrms sine wave, and ad

44、just the oscillator output so that the pointer of the set points at 9.0. 2) Adjust the TC so that the pointer points at 9.0 when the frequency is changed to 100 kHz while the oscillator output remains unchanged. PROCEDUREADJUSTMENT POINT 0 3 10 Scale 9 Scale 0-10 Scale 0-3 VT185(K)internet 98.7.30 1

45、6:00 y W 18 VT-185/VT-186/VT-187 10 PARTS LIST (UNIT) 186 L : ScandinaviaK : USAP : CanadaR : Mexico Y : PX(Far East, Hawaii)T : EuropeE : EuropeG : Germany Y : AAFES(Europe)X : AustraliaM : Other Areasindicates safety critical components. L : ScandinaviaK : USAP : CanadaR : Mexico Y : PX(Far East,

46、Hawaii)T : EuropeE : EuropeG : Germany Y : AAFES(Europe)X : AustraliaM : Other Areasindicates safety critical components. H10-2894-08FOAMED STYREN PAD H20-1750-08VINYL COVER W01-0522-08ACCESSORIES -W02-2358-08MAIN R UNIT(VT-185) -W02-2359-08MAIN R UNIT(VT-186/VT-187) -W02-2361-08MAIN L UNIT(VT-185) -W02-2362-08MAIN L UNIT(VT-186/VT-187) W02-2370-08POWER UNIT -W02-2371-08RANGE UNIT(VT-185) -W02-2372-08RANGE UNIT(VT-186) -W02-2373-08RANGE UNIT(VT-187) W02-2374-08METER UNIT -W02-2364-08CONTROL UNIT(VT-187) * New Parts Parts without