Tektronix VM700T, Руководство пользователя

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Appendix B: Performance Verification
B- 6
VM700T Option 01 (NTSC) & Option 11 (PAL) User Manual
26.
Disconnect the test equipment from the measurement set.
NOTE
. If the response on channel A is out of limits, your measurement set may
need readjustment of the system response. Refer your instrument to a qualified
service person.
If either channel B or channel C does not pass but channel A does, the Analog
input board may need replacement. Check with your nearest Tektronix represen-
tative or factory service for assistance and board replacement information.
This procedure checks the calibration of the internal oscillator using a signal
source of known frequency.
NOTE
. To successfully run this procedure, the internal oscillator of the measure-
ment set must be completely stable. Power on the measurement set at least 20
minutes before performing this procedure.
Test Equipment Required
H
Television signal generator (NTSC or PAL) with full field and burst
capability, accurate to
±
1 Hz.
H
Coaxial cable, 75 Ω high-quality noise free; 1-meter length.
H
Termination, 75
Ω
precision BNC.
Specification Checked
Burst frequency accurate to
±
10 Hz using the internal frequency reference.
NOTE
. The frequency of the signal generator used must be accurate to
±
1 Hz to
ensure a valid limit check reference on the burst frequency measurement.
Procedure: Measuring Burst Frequency
1.
Disconnect all signal inputs from the measurement set.
2. Press the Measure hard key and touch the Video soft key, if necessary, to
recall the Video measurement menu.
3.
Touch the Burst Frequency soft key. With no signal applied, the measure-
ment set displays a warning message that tells you to check the signal source
because a signal cannot be found. The burst frequency measurement starts
automatically after 3 seconds (the Loss of Sync indicator blinks).
Measure the Burst
Frequency
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