Standard Communications mt930b, Service Manual

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Maintenance
Page 6-18 Service Manual MT930B
Measurement Procedure (Manual):
Make the following measurements with the VM-700A in MANUAL mode:
• Chrominance–Luminance Delay
•
Chrominance–Luminance Gain
• Differential Gain (at 10–90% APL)
• Differential Phase (at 10–90% APL)
• Gain Frequency Distortion (Multiburst)
• Chrominance Nonlinear Gain
• Chrominance Nonlinear Phase
• Video S/N (C/N = 15.5 dB)
Measurement Specifications:
Refer to
Chapter 2, Specifications
, for all data.
Frequency Response Measurement (Composite Out 525/625)
Measurement Conditions:
• Video test signal: U704 video sweep (TG-7)
• Test equipment: Oscilloscope
Measurement Procedure:
Observe the video sweep wave on the oscilloscope, and measure the frequency
for the frequency given in the specifications, and convert the measurement to dB.
Measurement Specifications:
Frequency Response NTSC:
•
0.1 Hz to 6 MHz: ± 1.0 dB
•
6 MHz to 10 MHz: ± 3.0 dB
Frequency Response PA L:
•
0.1 Hz to 8 MHz: ± 1.0 dB
•
8 MHz to 10 MHz: ± 3.0 dB
Deviation Range for 1 V p-p Output Measurement
Measurement Procedure:
1. Set the video level to zero, and measure the video modulation when the
output waveform is 1 V p-p (maximum deviation range).
2. Set the video level to 100.0, and measure the video modulation when the
output waveform is 1 V p-p (minimum deviation range).
Measurement Specification:
Deviation Range for 1 V p-p Output:
•
10.0 to 27.6 MHz p-p (NTSC)
•
9.0 to 24.0 MHz p-p (PAL)