Avtech AVRF-4A-B, Instructions Manual

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FRONT PANEL CONTROLS
1. POWER Switch . This is the main power switch. When turning the instrument on,
there is normally a delay of 10 seconds before anything is shown on the main
display, as the internal operating system boots up.
If the main menu does not appear after 30 seconds, turn off the instrument and
leave it off for at least 60 seconds before applying power again.
2. OVERLOAD Indicator . When the instrument is powered, this indicator is normally
green, indicating normal operation. If this indicator is yellow, an internal automatic
overload protection circuit has been tripped. If the unit is overloaded (by operating at
an exceedingly high duty cycle or by operating into a very low impedance), the
protective circuit will disable the output of the instrument and turn the indicator light
yellow. The light will stay yellow (i.e. output disabled) for about 5 seconds after which
the instrument will attempt to re-enable the output (i.e. light green) for about 1
second. If the overload condition persists, the output will be disabled again (i.e. light
yellow) for another 5 seconds. If the overload condition has been removed, the
instrument will resume normal operation.
This overload indicator may flash yellow briefly at start-up. This is not a cause for
concern.
Note that the output stage will safely withstand a short-circuited load condition.
3. OUT CONNECTO R . This BNC connector provides the main output signal, into load
impedances of 50Ω .
Caution: Voltages as high as ±400V may be present on the center conductor of
this output connector. Avoid touching this conductor. Connect to this connector using
standard coaxial cable, to ensure that the center conductor is not exposed.
4. SYNC OUT . This connector supplies a SYNC output that can be used to trigger
other equipment, particularly oscilloscopes. This signal leads (or lags) the main
output by a duration set by the "DELAY" controls and has an approximate amplitude
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