Tektronix 475A - Trigger; Trigger Controls, Connectors, and

Fig. 4. Trigger controls, connectors, and indicators.
475A/DM44 Operators
lamp lit indicates intervals per second. H the duration of
one event is being measured, the Readout and Scale
Factor Lamps indicate frequency. The 1/ms lamp in-
dicates
kHz,
the
1/us
lamp
indicates
MHz,
and
no
lamp
lit
indicates
Hz.
24. Å TIME—Used in conjunction with the DELAY
TIME POSITION control in the TIME and 1/TIME func-
tions. The A TIME control moves only the time-
measurement point. The DELAY TIME POSITION contro}
moves both the reference point and the time-
measurement point. With the time-measurement point to
the left of the reference point the Readout indicates a
negative time difference.
NOTE
You can modify your instrument to make the DELAY
TIME POSITION contro! move only the reference
point, The procedure for making this modification is
focated in the Maintenance section of the DM44
Service manual.
TRIGGER
25. TRIG MODE—Determines the mode of trigger
operation for A Sweep.
AUTO: Sweep is initiated by the applied trigger signal.
In the absence of an adequate trigger signal, or if the
trigger repetition rate is less than about 20 hertz, the
sweep free runs and provides a bright reference trace.