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before performing an Auto test. Once the Auto Test is performed,
the units cannot be changed for that particular test. Soft keys allow
the operator to select 60, 120 (50, 100 Hz), or <1,000 Hz filters for
this measurement to help in troubleshooting. A 60 Hz modulation
component suggests a possible corroded connector, a 120 Hz compo-
nent tends to indicate a possible failure related to the DC supply in
the amplifier - possibly a capacitor going bad and aggravating the
ripple. A proprietary DSP technique enables Hum measurements on
modulated carriers (non-scrambled channels).
Information displayed in the Hum mode is as follows:
• Channel number
• Channel label, e.g. ESPN
• Video carrier frequency
• Hum value
• Hum filter frequency
• Channel plan
• Battery status
Stealth has been given the capability of measuring the 1Hz Hum
component. To activate this feature, set the Fundamental Hum
Frequency in the MEASUREMENTS setup screen to 1Hz. The
filter options on the Hum screen will then become; 1Hz, <50Hz, and,
<1kHz.
Summary of Contents for 3SR
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