Model 1707B Operation
SECTION 111
OPERATION
3-1. I NTR 0 D U CTI ON.
3-1 1. CALIBRATOR.
3-2. This section provides general operating instruc- 3-12. The 1-volt, l-kHz square wave output of the
tions and applications information for the Model calibrator can be used for vertical sensitivity calibr-
1707B. Front-and rear-panel controls and connectors ation and for divider probe compensation. The ampli-
are identified and briefly described in figure 3-1. tude accuracy is *l% and the frequency accuracy is
Operational adjustments are shown in figures 3-3 * 10'70.
and 3-4 and general operating instructions are shown
in figures 3-5 through 3-7.
3-13. FOCUS AND ASTIGMATISM.
3-3. CONTROLS AND CONNECTORS.
3-14. Both of these controls are used to obtain
a sharp display. Normally, the ASTIGMATISM con-
3-4. The following paragraphs explain some of the
trol need not be readjusted once it is set.
controls and connectors in detail.
3-15. COUPLING.
3-5. BEAM FINDER.
3-16. This lever switch selects either capacitive
3-6. Pressing this pushbutton increases intensity
(AC) or direct (DC) coupling of the input signal to
and reduces amplifier gain enough to return beam
the amplifier, or it grounds (GND) the amplifier
to viewing area. This enables the operator to locate
input stage while disconnecting the input signal.
beam and determine the action necessary to center
The switch should be positioned to DC when viewing
a display (examples: reduce input signal amplitude,
long duration pulses or dc levels of waveforms. AC
change coupling, adjust deflection factor, trigger
should be selected when viewing ac waveforms
level, dc balance, position controls, or intensity).
having large dc levels. GND position is used to
When centered properly, the beam remains on the
disconnect the signal source from the input of the
CRT when the pushbutton is released.
amplifier and at the same time grounds the input
of the amplifier. It is useful to use GND position
NOTE to establish a zero volt reference.
Due to phosphor burn sensitivity, instru- 3-17. DISPLAY.
ments with a P11 phosphor do not have
the intensified function of the beam 3-18. This switch selects the type of display. Input
finder. signals may be displayed either singly or simultane-
ously as explained below.
3-7. SCALE ILLUMINATION. 3-19. Position A displays channel A input signals.
3-8. This control adjusts the overall brightness of 3-20. Position B displays channel B input signals.
the CRT graticule. It should be adjusted for good
contrast between the background and graticule. The 3-21. Position A+B displays the algebraic sum of
SCALE ILLUM control is especially useful when the channel A and channel B input signals.
using a hood to view the display or when photo-
graphing waveforms. Rotate the control to OFF 3-22. CHOP position presents a separate display
when scale illumination is not needed. of each input. Both inputs are displayed during the
same sweep by switching between each channel at a
3-9. TRACE ALIGN. rate of 400 kHz, This mode should be used to display
low frequency signals. A ONLY TRIG should be
3-10. The TRACE ALIGN adjustment compensates used in the CHOP mode for stable triggering.
for external magnetic fields that may affect the
alignment of the horizontal trace with the graticule. 3-23. ALT position presents each channel on
The alignment should be checked when the instru- alternate sweeps. This mode should be used to dis-
ment is moved to a new location and adjustment play high frequency signals. If the channel A and B
made whenever necessary. signals are time related, A ONLY TRIG will provide
3- 1 |
ACEC
