Front Panel Controls; Installation - Tektronix 1S1 Instruction Manual

General Information
This section of the manual provides the basic information
required for operation of the Type 1S1. Instructions are in-
cluded for installing the unit, using the front-panel controls,
setting up the crt display, triggering the display and using
the Type 1S1 for making voltage and time measurements.
The Type 1S1 operates with the indicator oscilloscope to
form a complete sampling system, capable of viewing repeti-
tive waveforms with risetimes in the sub-nanosecond range or
frequencies up to more than one gigacycle. The "equivalent-
time" display is formed by taking samples from many cycles of
the waveform and reconstructing the waveform on the crt
screen. A bright crt display is produced, since each dis-
played dot is momentarily stationary, and the display repeti-
tion rate may be varied over a wide range by changing the
number of dots in the display. For a triggered display, each
dot requires a separate triggering event, rather than one
trigger per sweep as in a conventional real-time display.

Installation

To install the Type 1S1 in the oscilloscope, insert it into the
plug-in compartment and push it in as far as it will go.
Secure the unit by turning the securing-rod knob (at the bot-
tom of the front panel) clockwise until it is tight. The horizon-
tal deflection patch cord is then connected, as described
later under "First-Time Operation."
To remove the unit, disconnect the patch cord, then turn
the securing-rod knob counterclockwise until the rod feels
loose. Pull the Type 1S1 part of the way out of the compart-
ment with the knob, then take hold of the unit by the corner
rods to remove it from the oscilloscope.
The Type 1S1 may be removed or inserted without turning
off the oscilloscope power; however, it is recommended that
the power be turned off to protect the unit from transient
voltage surges that might occur as the various interconnecting
plug terminals make or break contact. If the power is left
on, be sure to turn down the crt beam intensity.
Whenever the Type 1S1 is transferred from one oscillo-
scope to another, the horizontal deflection factor of the oscil-
loscope must be adjusted and the "Operational Adjustments"
described later in this section should be checked. These op-
erational adjustment controls can all be reached either from
the front panel or from the left side of the unit after re-
moving the oscilloscope left side panel (or after extending a
rack-mounted oscilloscope). If the oscilloscope is operating
properly, the Type 1S1 should remain within the operating
specifications given in Section 1.
For checking circuits or for adjusting horizontal circuit
controls, the Type 1S1 can be operated on either a rigid
extension or a flexible extension cable. For normal opera-
tion, however, the unit should be installed directly in the
oscilloscope.
Cooling
The fan in the display oscilloscope provides forced-air
cooling of the Type 1S1. For proper circulation of air, the
oscilloscope should normally be operated with the side
panels in place. A constant temperature is important for
accurate operation of the instrument. Ambient air tem-
perature should not exceed 50° C (122° F).
FRONT-PANEL CONTROLS
All controls and connectors required for the normal op-
eration of the Type 1S1 are located on the front panel of
the unit (see Fig. 21). To make full use of the capabilities
of the instrument, the operator should be familiar with the
function and use of each of these controls and connectors.
Brief descriptions are presented in Table 2-1 and further
information, if necessary, is included later in this section
under an appropriate heading. The nature of the input
signal and the triggering signal will determine the setting
of the controls.
Functions of Controls and Connectors
VERTICAL
mVOLTS/CM Selects vertical input deflection factor from
Switch 7 calibrated steps ranging from 200 mv/cm
to 2 mv/cm. Deflection factor is calibrated
only when mVolts/Cm VARIABLE control
is at CAL position and VERT GAIN ad-
justment is set correctly.
mVolts/cm Varies vertical input deflection for adjust-
VARIABLE ing display amplitude between steps of
Control mVOLTS/CM switch. Extends deflection
factor to about 500[tv/cm from 2mv/cm
position of switch. When making voltage
measurements from display, be sure VARI-
ABLE control is set to CAL position. Does
not affect dc offset voltage measurement.
VERT Positions display vertically on oscilloscope
POSITION crt screen. Positioning range is slightly
Control greater than 10cm. Further vertical posi-
tioning is provided by DC OFFSET control.
DC OFFSET Positions display vertically on oscilloscope
Control crt screen by adding internal dc voltage
(+1 volt to -1 volt) to vertical signal.
Amount of offset voltage added to signal
(multiplied X10) can be accurately moni-
tored at OFFSET OUTPUT jack.
OFFSET Provides monitor output for determining
OUTPUT Jack amount of offset voltage added by DC
OFFSET control. Voltage change at OFF-
SET OUTPUT jack is 10 times the vertical
signal dc level change produced by DC
OFFSET control. Output impedance is
TABLE 2-1
2-1