DVG7 module adjustment procedures
ToadjusttheDVG7output
amplitude
Use this proced
ure to adjust the DVG7 output amplitude:
1. Set the DVG7 module for a 75% Color Bar signal output:
a. On the TG8000, press the MODULE button until the DVG7 module
main menu is displayed.
b. Press the BARS button until 75% Color Bars is displayed.
c. Press the ENTER button to confirm the selection.
2. Connect a 1 m high-bandwidth cable from the SIGNAL 1 output of the
module to the TCA75 BNC on the oscilloscope adapter.
3. Connect a 50 Ω cable from the SIGNAL 2 output on the DVG7 module
(through the BNC to SMA adapter (with or without the 6 dB pad) to the
trigger direct input on a sampling oscilloscope.
4. If necessary, set the oscilloscope as follows:
Time/Div: 2ns
Volts/Div: 100 mV
Averaging: 1
Record Length: 4000 points
5. On the scope, select Measurement 3, Pulse-Amplitude, and then Amplitude to
measure the amplitude on the flat part of the long pulse.
6. Right click on the mea surement readout, and select Show Statistics and Show
Annotations from the pop-up menu.
7. Note the expected average value, which is indicated by the letter μ, displayed
on the oscilloscope.
8. Press the Clear Data button on the oscilloscope and wait a bout 5 seconds
before proceeding to the next step.
9. Record the average value, which is indicated by the letter μ,intheSignal 1
amplitude row Before adjustment value column of the DVG7 output amplitude
t
able.
NOTE. If you entered the attenuation factor into the scope at the end of
the amplitude characterization procedure, then the scope will display the
multiplication result.
10. Locate variable resistor R507 on the D VG7 circuit board. (See Figure 9-1.)
11. Press the Clear Data button on the oscilloscope and wait about 5 seconds
before proceeding to the next step.
12. Adjust R507 so that the signal amplitude is equal to the height noted in step 7.
9–8 TG8000 Multiformat Test Signal Generator Service Manual
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