IBM 1403 Field Engineering Maintenance Manual page 68

Space Start Impulse (See Table 2, Figure 59)
Space Stop Impulse - (Triple - Space Sin gle - Shot Controlled)
e - Shot
Starts Timing Out
29
Millisecond Singl
V
~
....
/
i\
~
'--
\
...
,~
,;
~
Triple-Space Single-9..ot Set Early
Trace Shows Pull-In 19 Milliseconds
from Stop Impulse unti I Tractor Shaft
Is Settled
Triple-Space Single-9..ot Set Correctly
8 Milliseconds from
Stop Impulse until
Tractor Shaft Is Settled
Triple-Space Single-9..ot Set Late
Trace Shows Overshoot 23 Mill iseconds
from Stop Impulse until Tractor
Shaft Is Settled
(2V
/C~ (5MS/C~
29 Millise
Printing C
!
cond Single - Shot Times Out-
an Begin with Next PSS Pulse
Figure 63. Triple-Space Single-Shot Adjustments for Triple-
Spacing at 6 Lines per Inch (Model 6 Only)
5. Set the manual clutch to 8 lines-per-inch and re-
peat the check by the line trace or tach-generator
_ _ .. 1..._..1
UJt:UJUU.
6. The final adjustment of the triple-space single shot
is a compromise between minimum overshoot at 6
lines-per-inch and minimum pull-in at 8 lines-per-
inch. (This is also a compromise for the minimum
time from the impulse of the space-stop magnet un-
til the tractor shafts are settled down.)
Magnetic EmiHer Timing (Models 3, 4, 5, and 6.)
The space single shots must be correctly adjusted be-
fore adjusting the magnetic emitter timing.
68
1. Program for double-space (after print only).
2. Sync the scope on the impulse to the space-start
magnet.
3. Observe the time that the double-space single shot
times out.
4. Display the magnetic emitter impulse.
5.
Adjust the emitter timing so an emitter pulse starts
at the same time the double-space single shot times
out.
6. Program for triple-space (after print only).
7.
Observe the time that the triple-space single shot
times out. The magnetic emitter impulse for the
3-line skip should occur at the same time.
8. The final emitter timing is a compromise to provide
emitter pulses timed as closely as possible to the
time-out of both the double-space and triple-space
single shots.
9. Adjust the carriage tape sprocket so the stop brushes
make 1.5 (+.25, -0) milliseconds before the emitter
pulse.
Note: All other carriage tape-brush adjustments should
be made before the timing adjustrnent h maue.
The expedeJ
oscilloscope traces for skipping are shown in Figure 66. This
figure does not apply to the Model 6, which has no high-
speed skip function.
Magnetic Emitter Timing (Using Tach-Generator)
Note: This procedure is for Models 1 and 2 printers used with
1401 system. For printers used with other systems, refer to
systems manuals for timings.
1. Make sure the emitter is in correct adjustment as
described under
~fagnetic
Emitter Adjustment.
Then, set up the tach-generator and oscilloscope.
2. Set up a program for a triple-space loop at 6 lines
per inch.
3. Run the program and observe the scope trace.
4. Shift the emitter adjusting arm to obtain the least
time for the tractor shaft to stabilize. Figure 62
shows the way the trace should look.
Note: Using the line-graph method may indicate over-
shoot, pull-in, or squareness, but the best print alignment
occurs when the requirement of step 4 is met. The emitter
can also be rotated with respect to the shaft to adjust
emitter timing.
5. Change the program to a double-space loop at 8
lines per inch.
6. Run the program and observe the scope trace.