Sencore PS163 - 5 X Magnifier; Input Coupling; TV Vertical and TV Horizontal; 60 Cycle Sweep

Turn the CHANNEL A PPV PER DIV switch back to
the 1 position, and slide the SYNC POLARITY switch
back and forth between the POSITIVE and NEG-
ATIVE positions. Note that with the SYNC PO-
LARITY switch in the POSITIVE position, the first
half cycle of the displayed square wave is positive,
and with the switch in the NEGATIVE position the
first half cycle is negative.
Turn the TIME BASE - FREQUENCY switch counter-
clockwise to the 10mSec/DIV position, and back
clockwise to the .lmSec./DIV position. Note that
the slower the sweep speed, the larger the number of
displayed cycles and the faster the sweep speed, the
lower the number of displayed cycles. Leave the
TIME BASE - FREQUENCY switch set to .1mSec/
DIV.
Press the FREE RUNNING HORIZONTAL SWEEP
button, and note how the sweep loses sync. Adjust
the small center knob of the TIME BASE - FRE-
QUENCY switch to lock in the square wave. Note
that in the FREE RUNNING mode the horizontal
sweep is the same as on a conventional sync sweep
scope. The horizontal sweep frequency must be ad-
justed for a whole number of cycles of the displayed
waveform. Press the AUTO TRIGGERED HOR-
IZONTAL SWEEP button, and return the small knob
on the TIME BASE - FREQUENCY switch to the
full clockwise position.
5X MAGNIFIER
Turn the TIME BASE - FREQUENCY switch to the
.-omSec/DIV position, and adjust the small center
knob for 10 cycles of the displayed waveform in 10
divisions (one division per cycle). Pull on the HOR-
IZONTAL POSITION control to activate the 5X
EXPAND. Note that one cycle of the squarewave
now occupies 5 divisions. Push the HORIZONTAL
POSITION knob back in, and adjust it so that the
trace starts back at the left hand edge of the 10x10
grid. Return the small center knob to the full clock-
wise calibrated position.
INPUT COUPLING
Slide the CHANNEL A INPUT COUPLING switch
to the center ground position, and adjust the CHAN-
NEL A TRACE POSITION control so that the trace
is directly on the major horizontal grid line.
Slide the switch to the AC COUPLED position and
note that the square wave is two divisions high, and
that it is centered around the major horizontal grid
line.
Slide the switch to the DC COUPLED position. Note
that the square wave is still two divisions high, but
12
that it is now two divisions above the major hor-
izontal grid line. This indicates that the Cal VOLTS
2 V PP signal is changing from zero to positive, and
back to zero gain.
TV Vertical and TV Horizontal
Connect a stable color bar generator such as the Sen-
core CG159 to the antenna terminals of a properly
operating television receiver. Turn the pattern selector
of the color bar generator to the crosshatch pattern,
and adjust the receivers fine tuning, brightness and
contrast controls to properly display the crosshatch
pattern. Use the 39G34 LO CAP PROBE to connect
the PS163 CHANNEL A input to the base or control
grid of the first video amplifier stage. Adjust the con-
trols on the 25163 as follows:
HORIZONTAL SYNC INT.A
HORIZONTAL SWEEP AUTO TRIGGERED
TIME BASE - FREQUENCY TV V
VERTICAL INPUT A
CHANNEL A PPV PER DIV 1V/DIV
INPUT COUPLING AC COUPLED
Set the SYNC POLARITY switch to the POSITIVE
position if the sync pulses at the test point are pos-
itive, and to the NEGATIVE position if the sync
pulses are negative.
Turn the TIME BASE - FREQUENCY switch to the
TV H position, and note that in either the TV H or
TV V sweep positions, the composite video wave-
form remains stable.
Turn the color bar generator pattern selector to the
color bar position, and pull on the 25163 HORIZON-
TAL POSITION knob. Rotate the HORIZONTAL
POSITION control and note the expanded waveform.
Push the HORIZONTAL POSITION knob back in, and
adjust the HORIZONTAL POSITION control so the
waveform starts at the left hand edge of the 10x10.
grid.
60 Cycle Sweep
Use the 3934 LO CAP PROBE to connect approx-
imately 6.3 volts AC 60Hz from a filament circuit in
the receiver to the CHANNEL A input. Turn the
TIME BASE - FREQUENCY control to 60 Hertz
sweep. Adjust the CHANNEL A PPV PER DIV
switch for about 8 divisions of vertical deflection.