©PRINTED IN PAN
KENWOO
D
2 CHANNEL AC VOLTMETER
VT-175
INSTRUCTION MANUAL
KENWOOD
CORPORATION
Page 1: ... PRINTED IN PAN KENWOOD 2 CHANNEL AC VOLTMETER VT 175 INSTRUCTION MANUAL KENWOOD CORPORATION ...
Page 2: ... 2 F E A T U R E S 3 3 S P E C I F I C A T I O N S 4 4 F U N C T I O N A L C O N T R O L S 6 5 O P E R A T I O N 8 6 A P P L I C A T I O N S 10 7 M A I N T E N A N C E 13 8 A L I G N M E N T 14 9 C A U T I O N S F O R U S E 16 2 ...
Page 3: ...rom any overload in a very short time b Small sized compact construction is easy to carry and large sized two pointer meter is easy to read c Four scale dial plate and red and black pointers allow quick and accurate voltage reading d Number of adjusting trimmers are minimized with amplifiers that are precisely calculated in open loop gains and are negative feedbacked through metal film resistors a...
Page 4: ...00mV 1V 3 V 10 V 30 V 100V and 300V full scales d B 8 0 5 0 d B 0 d B 1 V dBm 80 52dBm 0dBm 1 mW 600n Error Within 3 of full scale at 1kHz Frequency response 10 at 5Hz 1 MHz 5 at 1 0 H z 5 0 0 k H z and 3 at 20 H z 2 0 0 k H z as 2 at 3 0 H z 1 0 0 k H z referenced to 1 kHz response Input impedance 1 0 M O 5 with less than 45pF parallel capacitance Durable input voltage 500V DC A C peak at 1V 300V...
Page 5: ...to noise ratio in 1 mV and 1V ranges Signal to noise ratio Over 40dB at full scale Frequency response Within 3dB at 5 Hz 500kHz Environmental Coefficient 0 08 C Temperature within specification 10 40 C full operation 0 50 C Relative humidity Less than 80 Power Supply Section Line voltage 100 120 220V A C 10 216 250V A C 50 60 Hz Power consumption Approx 7W Dimensions W x 190 212 H x 238 268 Dmm Va...
Page 6: ... F on off switch R A N G E C H 1 2 Channel 1 and 2 atten uator selector INPUT 1 Channel 1 input connector C H 2 S E L E C T O R Individual interlock range setting selector CH2 INPUT Channel 2 input connector R A N G E C H 2 Channel 2 attenuator selector GND M O D E Negative input floating switch Dual pointer meter Meter zero adjust trimmer CH1 left CH2 right 6 ...
Page 7: ...o IDENTSFSCA TION DESCRIPTION GND Casing grounding post CH2 O U T P U T Channel 2 monitor output connector Line voltage selector and fuse holder Power G a b l e connector CH1 O U T P Channel 1 monitor output connector CONT I N P U T Remote control mounting hole _ 7 _ ...
Page 8: ... N G E C H 2 selector to 300V To measure an A C voltage superimposed on a DC voltage be sure to set the selectors to the positions before connecting the cables to points to be measured r e r w i s e the DC voltage causes a high surge which could burn voltmeter 5 GND M O D E is effected with the switch released r in which both CH 1 and C H 2 are connected to the grounding terminal of the casing tak...
Page 9: ...evel on the scale be 1V with the R A N G E selector at 1 V a given voltage can be read as low as 6 0 d B 1 m V b y turning the selector downward Further as the scale A allows reading to 20dB 0 1 m V you can continuously measure the voltage ratio as high as 8 0 d B 0 1 mV to 1 V The read of 8 0 d B means a signal to noise ratio of around 10dB Also the dB scale allows continuous measuring up to 50dB...
Page 10: ...A C voltmeter In addition it provides a wide variety of applications as described below Amplifier Gain Measurement Voltmeter is capable of measuring an amplifier gain which is a signal magnification from point A to B in Figure 4 with a signal generator connected to the amplifier input If the measured signal levels at points A and B are a and b dB respectively then the gain is b a dB Figure 4 Ampli...
Page 11: ...ial Waveforms An voltmeter of absolute mean value indication type reads root mean square values of sinusoidal wave inputs Also it deflects the pointers in proportion to the absolute mean value of a given input wave If the form factor root mean square value absolute mean value of the input wave and the crest factor peak value root mean square value are known then the root mean square value and peak...
Page 12: ...R E O AMP CH2 S E L E C T O R swich to pressed interlock position as most stereo amplifiers are not deviated vertually in the left and right channel levels Set the GND M O D E switch to GND If the given stereo amplifier output has no connector common to the left and right channels then turnt he switch to O P E N a n d connect the GND post on the rear panel of voltmeter to that of the stereo amplif...
Page 13: ... is no longer operable If gone out check for a trouble cause remedy it remove the cap of the fuse holder on the rear panel using a minus screw driver and take it out and replace the fuse with a new one When replacing fuse be sure to check the capacity of a new fuse for a specified value as follows AC 100V 120V 0 5A A C 220V 240V 0 3A C H A N G E O V E R O F V O L T A G E IN SWITCHING R E G U L A T...
Page 14: ...ceed as follows Preset Controls on Side Panel see Figure9 The following controls placed on the Main PC board are to be preset on the right hand side panel I D E N T I F I C A TION DESCRIPTION TC101 First Attenuator preset trimmer capacitor VR101 First Attenuator preset variable resistor VR102 Meter Amplifier gain preset variable resistor 1 Before turning the O N O F F switch O N adjust the Meter z...
Page 15: ...voltmeter calibrator output voltage to 30mV 5 Adjust VR102 until the pointer swings to the fullscale 6 In turn set the R A N G E C H 1 2 selector to the 1 0 V range and set the voltmeter calibrator output voltage to 10V 7 Adjust VR101 until the pointer swings to the full scale 8 Disconnect the voltmeter calibrator and connect a wideband signal generator to the CH 1 INPUT con nector 9 Set the signa...
Page 16: ...areful of a line noise and similar small noises as your voltmeter is a highly sensitive voltmeter 6 Do not leave your VT 175 at any of high temperature and humidity places for a long period of time 7 As having two channel independent voltmeter your voltmeter is involved in selection of grounding point on some equipment udner measurement Set the GND M O D E switch to O P E N and connect the G N D p...
