4.2 Test Equipment
To test the 7200 scopes you will need the following equipment:
Two 50 ohm terminators. These may be purchased from Coline Ltd.
Precision D.C. Voltage source capable of 15mV to 1.5 Volts into a 50 ohm load. For this part of the test I use a DAC on the GPIB bus and an HP 34401A meter (also on GPIB) for feedback. The DAC has a buffer amplifier that has less than 10uV of noise. I did this arrangement because you will need to set the voltage to +/-15mV, +/-30mV, +/-60mV, +/- 150mV, +/- 300mV, +/- 600mV, +/-1.50V. The 1.5V has to be switched several times during checkout. Multiply this by two channels and you have 40 points you need to set, or in my case 80 points for a 4 channel scope. I am far to lazy.
Sine wave generator with a frequency 10KHz and 550mV RMS
Sine wave generator with a 10MHz, 225mV RMS output and an accuracy of less than 1 PPM
Square wave generator with a 10KHz, 700mV p-p output. The rise time must be less than 1nS.
Sine wave generator with a frequency range of 1 MHz to 501MHz . Used for testing bandwidth.
Ohm meter. Used to measure input impedance of each channel.
In my case I did not have a way to generate a square wave with a < 1nS rise/fall time. So, I built a small amplifier using an LVDS receiver from Pericom. These parts will take a 350mV signal and drive 3.3V logic level outputs with times around 350pS. I just run this circuit from my HP generator.
This is the final unit without the battery. The two SMA connectors are for the input and output. The switch is for the on/off.
Here is a plot from the LVDS drivers output. The battery close to dead and the voltage is way below the 3.3 Volts needed by the part, but it's still close to the required rise time.
4.3 7200A final Testing
This is the scope today. The unit now has two 7242Bs installed, SCSI, nice color display and running rock solid after a 10 hour burn-in test.
I played around a bit trying to show you what the display looks like, but this was the best I could do.
So far I have only found one company that can actually calibrate the 7200's plug-ins correctly, LeCroy. I was quoted $600, verbal, per 7242.
I ended up just testing the units on my own using a known calibrated equipment.
7200/A - Download the 7200 / 7200A Performance verification software for free. (200KB).
On-line calibration manual in Adobe PDF format
The following report was created from my 7200A using the LeCroy software.
7200A Mainframe SN: B21678 Plug-in A Model: 7242B-F2 Option L1 SN: 29157 Plug-in B Model: 7242B SN: 18117 7242B serial number B18117 7200A serial number B21678 Software version 3.3.1 DATE : 24 APR 2001 12:02:32 *********************************************************************** 7242B NOISE LIMIT TEST rev 2.0 S/N B18117 Spec: baseline noise limit <=1 mv at 5 mv/div T/div CH1 CH2 ********************************* 5.0 ms 100 uv 100 uv 2.0 ms 90 uv 100 uv 1.0 ms 90 uv 100 uv 0.5 ms 90 uv 100 uv 0.2 ms 90 uv 100 uv 0.1 ms 90 uv 100 uv 50.0 us 100 uv 100 uv 20.0 us 100 uv 100 uv 10.0 us 90 uv 100 uv 5.0 us 110 uv 110 uv 2.0 us 130 uv 140 uv 1.0 us 120 uv 140 uv 0.5 us 120 uv 140 uv 0.2 us 120 uv 130 uv 0.1 us 120 uv 140 uv 50.0 ns 110 uv 140 uv 20.0 ns 160 uv 340 uv 7242B NOISE TEST PASSED *********************************************************************** 7242B ADC NOISE TEST rev 2.1 S/N B18117 Spec: noise limit < lmv on 5mv/div range 5 ns/pt 2.5 ns/pt 1 ns/pt ******************************** CH1 180 uv 120 uv 130 uv CH2 150 uv 130 uv 150 uv 7242B ADC TEST PASSED *********************************************************************** 7242B DC LINEARITY AND GAIN TEST rev 2.0 S/N B18117 Spec: DC gain error limit < 2% V/DIV CH1 CH2 5 mv 1.6% 0.6% 10 mv 0.5% 1.7% 20 mv 1.3% 1.4% 50 mv 0.9% 1.2% 100 mv 1.0% 1.1% 200 mv 1.0% 1.0% 500 mv 0.6% 0.5% 1000 mv 0.5% 0.3% 2500 mv 0.3% 0.5% 7242B DC GAIN AND LINEARITY TEST PASSED *********************************************************************** 7242B TRIGGER LEVEL ACCURACY TEST rev 2.0 S/N B18117 Spec: max error < error limit (5% CH1 - 3, 10% Ext) Max Error CH Error Limit ************************* 1 4.7 % 5 % 2 3.9 % 5 % Ext 8.7 % 10 % 7242B Trigger Level Test PASSED *********************************************************************** 7242B TIMEBASE ACCURACY TEST rev 2.1 S/N B18117 Spec: difference to ref <= 100 Hz Reference frequency = 10.00 MHz Difference to reference frequency = 28.054 Hz 7242B TIMEBASE ACCURACY TEST PASSED *********************************************************************** 7242B TRIGGER DELAY ACCURACY TEST rev 2.1 S/N B18117 Spec: time at rise (TARS) limit <= 1ns Spec: time at fall (TAFL) limit <= 1ns Spec: overshoot limit <= 10% CH TARS TAFL OVSP OVSN 1 -0.143 ns -0.148ns 1.0% 0.0% 2 0.131 ns 0.154 ns 1.9% 0.0% 7242B TRIGGER DELAY ACCURACY AND PULSE RESPONSE TEST PASSED *********************************************************************** 7242B BANDWIDTH TEST rev 2.0 S/N B18117 Spec: 7242 BW 400MHz, 7242A, 7242B, 7234 BW 500 MHz Freq CH 1 CH 2 (MHZ) (mv) (mv) 1 115.3 114.9 2 113.5 114.2 11 110.7 110.1 21 110.7 111.4 51 107.9 109.6 101 103.6 106.4 201 99.4 102.2 301 91.6 98.3 401 82.7 93.4 501 71.4 84.5 7242B BANDWIDTH TEST PASSED *********************************************************************** 7242B INPUT IMPEDANCE TEST RESULTS S/N B18117 RANGE 50 ohms lMohm CH1 CH2 CH1 CH2 5mv 50.101 50.192 .99720 .99762 10mv 50.096 50.188 .99720 .99762 20mv 50.431 50.456 .99720 .99762 50mv 50.589 50.645 .99720 .99762 .lv 50.277 50.270 .99720 .99762 .2v 50.281 50.271 .99720 .99762 .5v 50.282 50.271 .99720 .99762 1v 50.282 50.192 .99720 .99762 limits (49-51 ohms) (980,000 - 1,020,000 ohms) *********************************************************************** * CALIBRATION CERTIFICATE * * * * The module and mainframe listed below has been * * checked and calibrated against our working standards * * listed below and following the procedure documented * * in the "7200 Series Precision Digital Oscilloscope * * 7234 & 7242 Series Module Calibration Procedure" * * Operators Manual. It meets or exceeds all published * * specifications. The standards used in this calibration * * traceable to the US National Institute of Standards * * and Technology (NIST). They are in compliance with * * MIL-STD 45662A. * * * * Mainframe model: 7200A SN B21678 * * Plugin model: 7242B SN B18117 * * Software version: 3.3.1 * * * * Temperature: 28C Humidity: 20% Technician: M. Wheeler * * * * Date of cal: 24 APR 2001 * * * * Approved by: * * * * Sinewave generator Cal Due Date: April 28,2001 * * Mfg. Marconi Model #: 2024 S/N: * * * * Square Wave generator Cal Due Date: April 28,2001 * * Mfg. HP Model #: 33120A S/N: US36001722 * * * * Precision DC Supply Cal Due Date: April 28,2001 * * Mfg. Custom Model #: Custom S/N: * * * * Volt / Ohm Meter Cal Due Date: April 28,2001 * * Mfg. HP Model #: 34401A S/N: US36033069 * * * * Power Meter Cal Due Date: April 28,2001 * * Mfg. HP Model #: 437B S/N: 3123U18605 * * * * Power Sensor Cal Due Date: April 28,2001 * * Mfg. HP Model #: 8482A S/N: 3318A27495 * * * *********************************************************************** 7242B serial number 29157 7200A serial number B21678 Software version 3.3.1 DATE : 24 APR 2001 14:31:12 *********************************************************************** 7242B NOISE LIMIT TEST rev 2.0 S/N 29157 Spec: baseline noise limit <=1 mv at 5 mv/div T/div CH1 CH2 ********************************* 5.0 ms 140 uv 140 uv 2.0 ms 140 uv 140 uv 1.0 ms 140 uv 150 uv 0.5 ms 140 uv 150 uv 0.2 ms 140 uv 140 uv 0.1 ms 140 uv 150 uv 50.0 us 140 uv 140 uv 20.0 us 140 uv 150 uv 10.0 us 150 uv 150 uv 5.0 us 160 uv 150 uv 2.0 us 160 uv 250 uv 1.0 us 160 uv 250 uv 0.5 us 170 uv 240 uv 0.2 us 160 uv 240 uv 0.1 us 160 uv 220 uv 50.0 ns 150 uv 230 uv 20.0 ns 150 uv 220 uv 7242B NOISE TEST PASSED *********************************************************************** 7242B ADC NOISE TEST rev 2.1 S/N 29157 Spec: noise limit < lmv on 5mv/div range 5 ns/pt 2.5 ns/pt 1 ns/pt ******************************** CH1 350 uv 170 uv 160 uv CH2 190 uv 160 uv 210 uv 7242B ADC TEST PASSED *********************************************************************** 7242B DC LINEARITY AND GAIN TEST rev 2.0 S/N 29157 Spec: DC gain error limit < 2% V/DIV CH1 CH2 10 mv 1.9% 1.7% 20 mv 1.0% 1.2% 50 mv 0.7% 0.7% 100 mv 0.4% 0.6% 200 mv 0.4% 0.7% 500 mv 1.0% 0.5% 1000 mv 0.5% 0.3% 2500 mv 0.1% 0.3% 7242B DC GAIN AND LINEARITY TEST PASSED *********************************************************************** 7242B TRIGGER LEVEL ACCURACY TEST rev 2.0 S/N 29157 Spec: max error < error limit (5% CH1 - 3, 10% Ext) Max Error CH Error Limit ************************* 1 3.4 % 5 % 2 3.3 % 5 % Ext 7.4 % 10 % 7242B Trigger Level Test PASSED *********************************************************************** 7242B TIMEBASE ACCURACY TEST rev 2.1 S/N 29157 Spec: difference to ref <= 100 Hz Reference frequency = 10.00 MHz Difference to reference frequency = 12.005 Hz 7242B TIMEBASE ACCURACY TEST PASSED *********************************************************************** 7242B TRIGGER DELAY ACCURACY TEST rev 2.1 S/N 29157 Spec: time at rise (TARS) limit <= 1ns Spec: time at fall (TAFL) limit <= 1ns Spec: overshoot limit <= 10% CH TARS TAFL OVSP OVSN 1 0.232 ns 0.246 ns 9.1% 4.1% 2 0.337 ns 0.364 ns 9.1% 6.0% 7242B TRIGGER DELAY ACCURACY AND PULSE RESPONSE TEST PASSED *********************************************************************** 7242B BANDWIDTH TEST rev 2.0 S/N 29157 Spec: 7242 BW 400MHz, 7242A, 7242B, 7234 BW 500 MHz Freq CH 1 CH 2 (MHZ) (mv) (mv) 1 118.1 116.3 2 117.4 116.7 11 115.3 112.8 21 115.3 110.0 51 115.3 113.2 101 114.6 115.3 201 114.2 116.3 301 111.0 110.3 401 111.7 110.7 501 93.7 89.8 7242B BANDWIDTH TEST PASSED *********************************************************************** 7242B INPUT IMPEDANCE TEST RESULTS S/N 29157 RANGE 50 ohms lMohm CH1 CH2 CH1 CH2 5mv 49.977 50.008 1.00157 1.00531 10mv 50.058 50.006 1.00157 1.00531 20mv 50.348 50.339 1.00157 1.00531 50mv 50.452 50.238 1.00157 1.00531 .lv 50.321 50.237 1.00157 1.00531 .2v 50.277 50.240 1.00157 1.00531 .5v 50.272 50.238 1.00157 1.00531 1v 50.272 50.238 1.00157 1.00531 limits (49-51 ohms) (980,000 - 1,020,000 ohms) *********************************************************************** * CALIBRATION CERTIFICATE * * * * The module and mainframe listed below has been * * checked and calibrated against our working standards * * listed below and following the procedure documented * * in the "7200 Series Precision Digital Oscilloscope * * 7234 & 7242 Series Module Calibration Procedure" * * Operators Manual. It meets or exceeds all published * * specifications. The standards used in this calibration * * traceable to the US National Institute of Standards * * and Technology (NIST). They are in compliance with * * MIL-STD 45662A. * * * * Mainframe model: 7200A SN B21678 * * Plugin model: 7242B SN 29157 * * Software version: 3.3.1 * * * * Temperature: 28C Humidity: 20% Technician: M. Wheeler * * * * Date of cal: 24 APR 2001 * * * * * * Approved by: * * * * Sinewave generator Cal Due Date: April 28,2001 * * Mfg. Marconi Model #: 2024 S/N: * * * * Square Wave generator Cal Due Date: April 28,2001 * * Mfg. HP Model #: 33120A S/N: US36001722 * * * * Precision DC Supply Cal Due Date: April 28,2001 * * Mfg. Custom Model #: Custom S/N: * * * * Volt / Ohm Meter Cal Due Date: April 28,2001 * * Mfg. HP Model #: 34401A S/N: US36033069 * * * * Power Meter Cal Due Date: April 28,2001 * * Mfg. HP Model #: 437B S/N: 3123U18605 * * * * Power Sensor Cal Due Date: April 28,2001 * * Mfg. HP Model #: 8482A S/N: 3318A27495 * * * ***********************************************************************