background image

Summary of Contents for CDC250

Page 1: ...User Manual Tek ronix CDC250 175 MHz Universal Counter 070 7999 02 ...

Page 2: ...User Manual Tek ronix CDC250 175 MHz Universal Counter 070 7999 02 ...

Page 3: ...n within the country in which the Tektronix service center is located Customer shall be responsible for paying all shipping charges duties taxes and any other charges for products returned to any other locations This warranty shall not apply to any defect failure or damage caused by improper use or improper or inadequate maintenance and care Tektronix shall not be obligated to furnish service unde...

Page 4: ...rpretation Display Instability Measurement Delays Intermeasurement Interval Measurements Frequency Measurements Period Measurements Frequency Ratio Measurements Time Interval Measurements Totalize Measurements Checking Instrument Operation 9 9 10 11 11 12 12 15 15 16 18 19 21 24 25 Appendix A Specifications 27 Appendix 8 Maintenance Cleaning Preparing for Shipment Troubleshooting No Display with P...

Page 5: ...autions Use Proper Power Cord To avoid fire hazard use only the power cord specified for this product Avoid Electric Overload To avoid electric shock or fire hazard do not apply a voltage to a terminal that is outside the range specrified for that terminal Ground the Product This product is grounded through the grounding conductor of the power cord To avoid electric shock the grounding conductor m...

Page 6: ... damage to this product have it inspected by qualified service personnel lv CDC250 User Manual General Safety Summary Safety Terms and Symbols Terms in This Manual These terms may appear in this manual A A WARNING Warning statements identify conditions or practices that could result in injury or loss Of life CAUTION Caution statements identify conditions or practices that could result in damage to...

Page 7: ...d an LED indicator shows the display measurement unit In addition to frequency measurements the frequency counter provides the following measurement functions I Period measurements in microseconds or milliseconds over a 5 Hz to 2 MHz range I Frequency ratio measurements comparing two input signals I Time interval measurements from a selected edge of one input signal to a selected edge of another I...

Page 8: ...or replacing the fuse 2 Check that the correct line fuse is installed The line fuse provides protection if the equipment malfunctions or an overload occurs FLefer to Appendix C Replaceable Parts on pa ge 37 for fuse part numbers CDC250 User Manual Getting Started A WARNING Ilo prevent electrical shock connect the power cord to a properly grounded power source The outside ground Of this connector i...

Page 9: ... signal readings are in kHz or MHz as selected by the MHz ms kHz pus switch item 13 Resolution is as selected by the GATE switch item 11 4 CDC250 User Manual Getting Started I PERIOD The period of one cycle of the CHANNEL A INPUT signal is displayed Display reading is in milliseconds or microseconds as selected by the MHz ms kHz pus switch item 13 Resolution is as selected by the GATE switch item ...

Page 10: ...or triggering When ON button in the negative going edge is selected when OFF button out the positive going edge is selected 18 CHANNEL A INPUT VOLTAGE Switch When set to 3 V42 V HI button in the CHANNEL A INPUT signal is attenuated by a factor of ten before application to the counter When set to 50 mv 5 V LO button out the signal is not attenuated 19 CHANNEL A INPUT Connector BNC connector for 5 H...

Page 11: ...ve nwanted transients radio frequency interference RFI or other types of noise that may cause a counting error Duty Cycle Measurements The TIME Interval mode can be used to determine the duty cycle of a digital wave form by applying the same signal to CHANNEL A and CHANNEL 8 and selecting the proper edges for triggering For an example refer to Figure 4 The duty cycle or ratio of on time to total p...

Page 12: ...ution is gained In PERIOD mode the possibility of error is constant for all GATE times 10 CDC250 User Manual Reference Using TI lG LEVEL Control When pushed in PRESET the TRIG LEVEL control sets the trigger threshold to the approximate average of the CHANNEL A signal While this is sufficient for many signals it is not adequate for the wave form pictured in Figure 5 The lower dotted line represents...

Page 13: ...digits can be obtained lessening the effects of instability by using PERIOD mode High frequency accuracy is enhanced by using FREQuency mode The crossover point between the two modes is 10 kHz Measurement Delays In all measurements except TOTALize the display is updated at the end of a finite measurement interval which varies in length according to the operating mode and resolution selected For so...

Page 14: ...cy does not affect measurement time in RATIO measurments 14 CDC250 User Manual Reference Table 3 GATE Setting and CHANNEL 8 Counts GATE Setting CH 8 counts to 0 01 s 1 0 1s 10 ls loo 10s 1000 Intermeasurement Interval The time interval between measurements GATE indicator off is fixed at 200 ms in all modes except FREQuency MHz where it is 400 ms and in TOTALize mode where counting is continuous Th...

Page 15: ...asurement is completed 16 CDC250 User Manual Reference 6 Push in and release the RESET switch to reset the display to Zero The following input controls can be used to condition the input as needed to prevent miscounting from input noise or ringing LOW PASS FILTER Engaging the LOW PASS FILTER switch routes the CHANNEL A input through a low pass filter before application to the counter This helps el...

Page 16: ...lay is exceeded 18 CDC250 User Manual Reference NOTE If measurement delay and display instability are encountered see Display Interpretation o pc gc I 5 Engage the HOLD switch button in to lock the display at the existing reading Release the HOLD switch When HOLD is released button out a new measurement begins GATE indicator lights but the display continues to hold the old reading until the new me...

Page 17: ...PUT VOLTAGE SLOPE and TRIG LEVEL can be used to condition the CHANNEL A input The CHANNEL 8 INPUT controls INPUT VOLTAGE and SLOPE can be used to condition the CHANNEL 8 input Refer to the description of input controls on page 17 Time Interval Measurements ln TIME mode the unit measiires the elapsed time from a selected edge of the CHANNEL A wave form to a selected edge of the CHANNEL 8 wave form ...

Page 18: ...switch When HOLD is released a new measurement begins GATE indicator lights but the display continues to hold the old reading until the new measurement is completed 22 CDC250 User Manual Reference 8 Push the RESET switch in to reset the display to zero Release the RESET switch When RESET is released a new measurement begins GATE indicator lights but the display remains at zero until the new measur...

Page 19: ...ain 4 Stop counting by one of three methods I Send a low gating signal to the TOTALIZE INPUT START STOP connector Counting stops and the display is held at the accumulated total Counting resumes when the gating signal again goes high 24 CDC250 User Manual Reference NOTE The gating signal at the TOTALIZE INPUT START STOP connector halts totalization by inhibiting the CHANNEL A input signal It also ...

Page 20: ...ton 9 Check that the GAIT indicator resumes flashing and the display updates at the end of the first GAIE interval 26 CDC250 User Manual prj Appendix A Specifications Characteristics after one hour warmup time at 23 C 5 C 75 RH Table 5 Operational Characteristics Frequency FlangekHzMode 5 Hz to 10 MHz MHz Mode 5 MHz to 175 MHz Accuracy 1 count time base error Besolution 0 1 Hz to 1 kHz in decade s...

Page 21: ... with S N ratio better than 40 dB 2 N numberofcyclesaveraged 1 10 100 orl000 28 CDC250 User Manual Appendix A Specifications Table 5 Operational Characteristics Cont CHANNEL A Input MHz Mode5MHz to 125 MHz 50 in V s 125 MHz to 150 MHz 100 in VRMs 150 MHz to 175 MHz 150 in VBMs Impedance 1 MQ paralleled by 40 pF MaximumInputvoltage 42 Vpk Attenuation Times 1 or times 10 selectable Filter Low pass 1...

Page 22: ...ed 400 ms interval PEBIOD PIATIO and TIME User selected cycles averaging of 1 10 100 or 1000 cycles Modes plus fixed 200 ms interval TOTALIZE Mode Continuous Table 6 Physical Characteristics Physical Width 240 mm 9 5 in Height 64 mm 2 5 in Depth 230 mm 9 0 in Weight 2 0 kg 4 4 lb Table 7 Environmental Characteristics Environmental Operating Temperature oo c to 4oo C 75 o PIH Storage Temperature 2o...

Page 23: ...benzine benzene toluene xylene acetone or similar solvents Do not use abl asive cleaners on any portion of the frequency counter Preparing for Shipment If the original packaging is unfit for use or not available use the following packaging guidelines 1 Use a corrugated cardboard shipping carton having inside dimensions at least three inches greater than the instrument dimensions 2 Put the instrume...

Page 24: ...king continuity 3 If outlet voltage is correct check power cord continuity If the power cord fails the continuity check replace the power cord 4 If the power cord passes the continuity check refer to the nearest Tektronix service center for repair CDC250 User Manual Appendix 8 Maintenance Display On but Frequency Not Counted If the display is on but the frequency counter does not count do the foll...

Page 25: ...al Counter Table 9 Standard Accessories Accessory Tektronix Part Number Fuse 3AG 0 250 A 250 V SB 159 0187 00 90 132 V operation CDC250 User Manual 070 7999 XX 115 V Power Cord Plefer to Table 11 Optional Accessories The following items are available as optional accessories Table 10 Optional Accessories Accessory Tektronix Part Number Fuse 3AG 0 125 A 250 V SB 159 0313 00 198 250 V operation 230 V...

Page 26: ... Accessory Power Cords Plug Configuration Normal Usage Tektronix PartNumber North America115V 161 0104 00 Q Zfo Europe230V 161 0104 06 United Kingdom230V 161 0104 07 I Australia230V 161 0104 05 o North Amerlca230V 161 0104 08 cs Switzerland230V 161 0167 00 38 CDC250 User Manual ...

Reviews: