Wavecrest DTS-2070 Manual

WAVECREST Corporation
Calibration Procedure for the DTS-2070
Time Measurement System

WAVECREST Corporation continually engages in research related to
product improvement. New material, production methods, and design
refinements are introduced into existing products without notice as a
routine expression of that philosophy. For this reason, any current
WAVECREST product may differ in some respect from its published
description but will always equal or exceed the original design
specifications unless otherwise stated.
Copyright 1998
WAVECREST Corporation
A Technologies Company
7275 Bush Lake Road
Edina, Minnesota 55439
[phone]
[phone]
All Rights Reserved
Rev. 1.0

WAVECREST Corporation
DTS-2070C Calibration Procedure (17 April 1998)
1
CALIBRATION PROCEDURE FOR DTS-2070C
TIME MEASUREMENT SYSTEM
Equipment Required: 1 Frequency counter with high stability time base (9½ digit resolution)
1 Digital voltmeter (6½ digit resolution)
1 Variable output power supply (Ø-6 VDC)
3 50 ohm SMA connectorized cables of equal length (approximately
1 meter)
1 5/64" Hex wrench
1 Straight blade screwdriver, medium
1 Small, non-conductive straight blade screwdriver tool for
adjusting oscillator
1 DTS-2070C User's Guide
4 SMA shorting caps provided with the system
A/R Connector adapters as required to interface listed equipment
with SMA cables
1 Oscilloscope with 1 GHz minimum bandwidth
1 Calibrated delay line with SMA interconnects
1 Function generator with outputs to 100 KHz and a variable duty
cycle adjustment (pulse width).
1 Computer with GPIB interface and cable
1 “Virtual Instruments” -or- calibration software
Notes: 1) Use only electronic test equipment with calibrations traceable to NIST standards.
2) Refer to the DTS-2070C User’s Guide for general operating instructions.
3) For all measurements using the DTS-2070C, the system’s cover should be installed and
the system should be allowed to warm-up at least 15 minutes.
4) All calibration operations should be made at a grounded workstation while wearing
a grounded strap.
1.0 Removal of the System Top and Bottom Covers
(1-1) Place the system on a sturdy horizontal surface such as a workbench. The system should
be resting on all four feet. Verify the AC power cord is not connected at this time.
(1-2) Using the Hex wrench, remove (3) screws from the left and (3) screws from the right side
panels. Then remove (15) screws from the top side.
(1-3) While slightly spreading the side panels from the bottom, lift the cover straight up until
clear of the system. Store cover and screws in a safe place.
(1-4) Turn DTS system over, so the top is resting on the workbench, and the bottom cover is
facing up.

WAVECREST Corporation
DTS-2070C Calibration Procedure (17 April 1998)
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(1-5) Using the hex wrench, remove the screws from the bottom. Store cover and screws in a
safe place.
(1-6) Turn DTS system over, so that the front panel is right side up. Then connect the AC
power cord to the rear of the DTS. Ensure that the main DTS power switch and front
panel standby switch are both off.
CAUTION: With the cover removed for servicing, there are areas of exposed AC voltage at the
power supply terminal blocks and in the area of the fans. To avoid exposure to
these hazardous voltages, use extreme caution making adjustments to the power
supplies with the power on.
Note: The DTS-2070C system is most accurate when the system temperature has reached
a stable condition. The system should be allowed to warm up with the power "ON"
for at least 1 hour prior to beginning the calibration procedure. The power should
be left "ON" as often as possible throughout the calibration.
2.0 Power Supply Checks
(2-1) Verify the AC power cord is connected to an appropriate power source (110V/60 Hz) or
(230V/50 Hz). Turn on the main power switch at the rear of the system. Then turn on the
standby switch on the front panel. Verify the display illuminates, both fans are blowing
air OUT of the system, and the system initiates its self test routine.
Make the following measurements referenced to chassis ground and adjust the power
supply outputs if necessary.
Record the following voltage readings on the test data record (before and after adjustment).
(2-2) Using the voltmeter, measure the (+OUT) output of the +15VDC power supply (orange
wire) at connector J2, shown in Figure 1A. Verify the voltage is +15VDC ±0.15V. If
necessary, adjust +15VDC at VOUT on the ±15V module.
(2-3) Using the voltmeter, measure the (-OUT) output of the ±15VDC power supply (blue
wire) at connector J2, shown in Figure 1A. Verify the voltage is -15VDC ±0.15V. If
necessary, adjust -15VDC at OVP on the ±15V module.
(2-4) Using the voltmeter, measure the (+OUT) output of the +24VDC power supply (yellow
wire) at connector J2, shown in Figure 1A. Verify the voltage is +24VDC +0.24V. If
necessary, adjust the +24VDC supply.
(2-5) Using the voltmeter, measure the (+OUT) output of the +5VDC power supply (red wire)
at TP2 on the backplane referenced to ground. Verify the voltage is +5VDC +0.05V. If
necessary, adjust the main supply adjustment.

WAVECREST Corporation
DTS-2070C Calibration Procedure (17 April 1998)
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(2-6) Using the voltmeter, measure -5VDC at TP3 of the back plane. Verify the voltage is
-5VDC ±0.05V. If adjustment is required, the -5VDC module closest to the DTS front
panel must be adjusted at VOUT.
(2-7) Using the voltmeter, measure -5VDC at the location shown in Figure 1B on the TMU470
board. Verify the voltage is -5VDC +0.05V. If adjustment is required, the -5VDC
module closest to the DTS center bulkhead must be adjusted at VOUT.
(2-8) Using the voltmeter, measure -2VDC at TP4 of the back plane. Verify the voltage is
-2VDC +0.02V.
Reference Voltage Check
(2-9) Using the digital voltmeter, probe the red and black pin jacks located on the back panel of
the DTS, verify the DC voltage reads within ±1.1m VDC of the value recorded on the
previous calibration label. Record this value in the test data record.
-15 VDC
+24 VDC
J2 Filter
Board
+15 VDC
Figure 1A
TMU470 Board
-5 VDC
Front of DTS
Figure 1B

WAVECREST Corporation
DTS-2070C Calibration Procedure (17 April 1998)
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3.0 100 MHz Oscillator Check
(3-1) Connect one SMA cable to the l00 MHz reference clock output at the back of the unit.
Connect the SMA cable to the frequency counter (50 ohm input) and verify the oscillator
output is 100.0 MHz ±0.9 Hz.
If necessary, remove the screw on the top surface of the oscillator located in the front half
of the system, and use the non-conductive adjustment tool to change the oscillator
frequency. (Clockwise adjusts the frequency down.) Allow frequency to settle for one to
two minutes before readjustment.
(3-2) When adjusted properly, install screw into oscillator. Re-install top and bottom covers,
but do not put screws in the top cover at this time. Allow system to run for one hour
before proceeding.
(3-3) Repeat the oscillator check and verify the oscillator output is 100 MHz ±0.9 Hz before
proceeding. When ready to proceed, install the screws in the top cover.
4.0 Self Calibration
Note: The (4) shorting caps and (2) 36” SMA cables provided with the system will be used
in the following steps.
(4-1) Initiate an internal calibration sequence by pushing the INT CAL button on the front
panel. The display will indicate the time remaining to accomplish the internal calibration,
counting down on the display. When the countdown reaches 0 seconds, the display will
change to: CALIBRATED. The previous mode and display then returns.
(4-2) Press the EXT CAL button on the front panel. The display will direct the user from the
front panel. Both the DC and AC calibrations should be done at this time. Follow the
instruction prompts on the front panel display. DO NOT use shorting caps on the CAL1
or CAL2 output connectors. Use only on CH1, CH2, ARM1 and ARM2 connectors.
When the instrument completes its calibration sequence, the DTS will display
CALIBRATED. The previous mode and display then returns.
(4-3) With the DTS connected to a computer, use the “Virtual Instruments” software or
calibration software to first perform the DTS connect sequence over the GPIB interface,
then perform the STROBE CAL operation. Follow the instructions on the computer
display. When the strobe calibration has completed successfully, exit the program and
disconnect the GPIB interface.
This completes the calibration portion of this procedure. The remaining steps are performance
verification steps to ensure the system is operating properly.

WAVECREST Corporation
DTS-2070C Calibration Procedure (17 April 1998)
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5.0 Reference Voltage Operational Check
(5-1) Using the voltmeter, set the power supply for each value shown in Table 1. Then remove
the voltmeter and connect the power supply to the DTS CH1. Press the "FUNC" key to
perform a pulse find operation. The displayed voltages at Menu #5 for CH1 should be
between the values shown in Table 1. (see Figure 1-6 in the User’s Guide)
Table 1. Input Voltage Correlation
Selected Voltage Min Reading Max Reading
-1.000V -1.0025V -0.9975V
-0.250V -0.2522V -0.2478V
-0.025V -0.0271V -0.0229V
+0.025V +0.0229V +0.0271V
+0.250V +0.2478V +0.2522V
+1.000V +0.9975V +1.0025V
(5-2) Repeat for CH2.
Note: Depending on the power supply drive capability, the 50 ohm input impedance of the
DTS may result in slightly lower readings on the DTS display. It may be necessary to
measure and set the DC voltage at the DTS input connectors using a “T” adapter.
6.0 Calibration Signal Outputs
(6-1) Using the frequency counter and the oscilloscope and BNC-SMA adapter, if required,
measure the outputs of both the CAL1 and CAL2 connectors. Verify the outputs are:
2.0Vpp ± 0.2V
200 MHz ± 200 Hz
Note: It is necessary to terminate both CAL outputs to 50 ohms when measuring outputs.
This can be done by measuring one channel while externally triggering from the
other output channel.
(6-2) Connect the CAL1 to the CH1 channel, and the CAL2 to the CH2 channel using the SMA
coax cables.
(6-3) Go to Menu #15 and change MEASURE to ON. Then press the BURST button on the
front panel. The display will read: Subsequent cables will use this cable arrangement
as a reference. To verify this, press BURST again. The value displayed should be less
than two picoseconds.
(6-4) Place the delay line between the CH1 input and the SMA cable connected to CAL1.
Verify that CAL2 is connected to the CH2 input.

WAVECREST Corporation
DTS-2070C Calibration Procedure (17 April 1998)
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(6-5) Press the BURST button on the front panel. Verify the "electrical length" of the cable
delay line being measured (in picoseconds) is within ±10 psec of the calibrated length.
(6-6) Set MEASUREMENT to OFF and remove the delay line.
7.0 AC Performance Checks
This step turns on the 200 MHz calibration signal following the cable measurement step.
(7-1) Verify that CAL1 is connected to CH1 and CAL2 is connected to CH2. Press the EXT
CAL button on the front panel. The display will direct the user from the front panel.
Perform only the AC external calibration at this time. (Do not press “GO” for DC Cal.)
When the instrument completes its calibration sequence, the DTS will display
CALIBRATED. The previous mode and display then returns.
(7-2) Go to Menu #1 (see Figure 1-6 in the User's Guide) and place the cursor on the CLEAR
field. Then press FUNC. This sets up the DTS in a known defaults state.
(7-3) Go to Menu #4 and set the Number of Readings (sample size) to l0,000, SETS to l, and
press CONT. Then go to Menu #7.
(7-4) With the TRIG field set to 50%-50%, scroll through the various measurement options
shown below and record the measurements. Verify JITTER (JTrms) measures <6ps
(>2KHz for frequency). Then connect CAL1 to CH2 and CAL2 to CH1. Scroll through
the various measurement options shown below and record the measurements. Average
the two sets of measurements recorded for each measurement option. The average should
be within the limits shown below.
*Both Channels
TPD++ 0.000 psec ±10 psec
TPD-- 0.000 psec ±10 psec
TPD+- 2500.000 psec ±10 psec
TPD-+ 2500.000 psec ±10 psec
PW+* 2500.000 psec ±10 psec
PW-* 2500.000 psec ±10 psec
PERIOD* 5000.000 psec ±10 psec
FREQ* 200.0 MHz ±1 KHz
(7-5) Scroll to TT+ and press FUNC. The TT+ and TT- measurements for both input channels
are now set for 10%-90% trigger levels and should read between 1400 psec and 1500 psec.
Note: When selecting Channel 2 in step (7-5), it will be necessary to press FUNC to
perform a pulse find measurement on Channel 2 to get the proper results.

WAVECREST Corporation
DTS-2070C Calibration Procedure (17 April 1998)
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8.0 Arming and Gating Checks
(8-1) Connect CAL2 to the ARM1 input channel. Connect CAL1 to the delay line and the
delay line to the CH1 input channel.
(8-2) At Menu #7, select PERIOD, CH1, TRIG = 50%-50%. Select AUTO ARM and
CONTINUOUS mode on the front panel, and press FUNC. Verify the displayed
measurement is 5000 psec ±10 psec with JITTER <6 psec.
(8-3) Set the function generator to output a square wave with a 5 nsec wide duty cycle, and a
1V pk-pk signal at 1 KHz.
(8-4) Select EXTERNAL ARMING on ARM2 mode. Verify sample size = 10,000.
(8-5) Connect the CAL1 to the CH1 input channel and CAL2 to the CH2 input channel.
Connect the output of the function generator to the ARM2 input. Go to Menu #9 and set
GATE = “ON H”. Then press CONTINUOUS.
(8-6) Determine the approximate amount of time it takes the DTS to obtain l0,000 samples.
This can be done by watching Menu #6. Then change the gating duty cycle on the
function generator from 5 nsec to 2 nsec. The time to obtain the 10,000 samples should
now be more than twice as long.
(8-7) Remove all test equipment and cabling from the DTS.
9.0 Shut Down the DTS System
(9-1) Go to Menu #1 and select CLEAR. Then press FUNC to return the system to the default
state.
(9-2) Power off the standby switch on the front panel and the main power switch on the rear of
the instrument. Remove all cables and unplug the AC power cord from the power source
and package the accessories that accompanied the system for return to the customer.
9.1 End of Calibration Procedure
If any display function does not appear to provide reasonable results, notify the
WAVECREST Corporation factory for support at 1-800-733-7128.

WAVECREST Corporation
DTS-2070C Calibration Procedure (17 April 1998)
8
REQUEST FOR
NOTIFICATION OF FUTURE PROCEDURE UPDATES
NOTICE TO RECIPIENT:
If you would like to be included in the distribution of new versions of this calibration procedure in the
future, please indicate this to us by mailing this form back to Wavecrest Corp. at the address shown
below, or fax it to the Director of Quality at (612) 831 - 4474.
Wavecrest Corp.
7275 Bush Lake Road
Edina, MN 55439
Yes, please include me when you distribute future new versions of the DTS-2070C Calibration
Procedure.
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WAVECREST Corporation WAVECREST Corporation
World Headquarters West Coast Office:
7275 BushLake Road 1735 TechnologyDrive, Suite 400
Edina, MN 55439SanJose, CA95110
[phone] [phone]
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