Tektronix 3 - Page 7

computer system should not be interwound with
the input leads to the oscilloscope. Maximum
separation of the leads is recommended since
there is a magnetic field present when the Electric
Shutter solenoid is energized.
Focusing with Electric Shutter
The aperture opening is controlled and selected in a normal
manner. The shutter blades may be opened for focusing by
setting the Speed switch on the Speedcomputer to (T)
and pressing the ACTUATE pushbutton once to open the shut-
ter blades and pressing it again, when finished focusing, to
close the shutter blades. Another method is to press the
Press Focus lever on the side of the shutter assembly down
to open the shutter blades and either lifting the Press Focus
lever up to close the shutter blades or pressing the ACTUATE
pushbutton until the SHUTTER indicator lamp goes out (once
for any speed setting except (T) and twice for a (T) speed
setting).
Photographing Repetitive Waveforms
Mount the Electric Shutter and Speedcomputer on the cam-
era as described under Mounting, then mount the camera
on the oscilloscope.
1. After connecting the Electric Shutter to the Speedcom-
puter, apply line voltage to the Speedcomputer, then set the
Speed selector to any speed, for example 2 ('/ s).
2. Open the shutter blades by lifting the Press Focus lever.
3. Focus the camera.
4. After focusing the camera, close the shutter blades by
turning on the Speedcomputer and pressing the ACTUATE
pushbutton.
Operating Instructions—No. 3 Electric Shutter
To photograph a repetitive waveform, using any shutter
setting other than (T) or (B), first obtain a stable display of
the desired waveform on the CRT. Second, with the camera
back ready for exposure, push the ACTUATE pushbutton
and release.
To photograph a repetitive waveform using a shutter set-
ting of (T), the ACTUATE pushbutton must be pushed twice.
The first time it is pushed, the shutter will open. The second
operation will close the shutter.
To photograph a repetitive waveform using a shutter set-
ting of (B), the ACTUATE pushbutton must be held in the
pushed-in position for the desired exposure time and then
released.
Photographing Non-Repetitive Waveforms
Mount and focus the camera system as described previously
under “Photographing Repetitive Waveforms."
When photographing a non-repetitive waveform using a
Speedcomputer Speed setting of (T), set the oscilloscope for
single-sweep operation so that the display, when presented,
will not have jitter. Push the ACTUATE pushbutton to open
the shutter blades. Wait for the waveform to occur, then push
the ACTUATE pushbutton to close the shutter blades.
When using a Speedcomputer speed setting of (B) to photo-
graph a non-repetitive waveform, set the oscilloscope for
singe-sweep operation. Then push the ACTUATE pushbutton
in and hold it for the duration of the waveform. After the
waveform has occurred, then release the pushbutton to close
the shutter blades.
NOTE
In (T) the shutter blades can remain open for an
indefinite time without any damage to the Electric
Shutter of Speedcomputer.