Avtech AVMH-4, Инструкция по эксплуатации

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FRONT PANEL CONTROLS
1. POWER Switch. This is the main power switch. When turning the instrument on,
there may be a delay of several seconds before the instrument appears to respond.
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.
3. PRF Range Switch and Fine Dial. This switch sets the pulse repetition frequency
(PRF) range of the internal oscillator. The marked value of each position is the
upper limit of the range, approximately. The fine dial directly below the switch varies
the PRF within the set range. When set to the “EXT” position, the instrument is
triggered by externally-generated pulses applied to the TRIG input.
4. DELAY Control. Controls the relative delay between the reference output pulse
provided at the SYNC output and the main output. This delay is variable over the
range of 0 to 50 ns, approximately. At high frequencies, this delay should be kept
nearly fully counter-clockwise, so that the delay does not exceed the period
(otherwise, the triggering may stop). The variable delay circuitry only functions in the
internal trigger mode. The delay is not adjustable when triggering externally.
If the output pulse appears to be unstable or jittery, it may be necessary to adjust the
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