TM 11-6625-3025-14/ET426-AA-MMA-010/E154 VII210/T.O. 33A1-8-902-1-1
often derived from a crystal oscillator, in which case a repetition rate tolerance of 0.01% can be assumed unless specified
otherwise. If the line lock mode is used in sync generation, accuracy can be defined only by the stability of the reference
power line signal. Synchronizing pulse inputs govern accuracy and stability of the test pattern signal.
b. Adjustment Procedure. The generator is adjusted using an individual procedure for each test pattern, which
is complete in itself except the output must be checked first to verify basic signal levels and proportions. For adjustments
of all signals, observe the output composite video signal at the video output connector on the rear panel. Refer to circuit
ard and control locations, figure FO-21, if adjustments are necessary.
(1) Connect the test pattern generator for use as shown in figure 2-1.
NOTE
If the test pattern generator does not have an internal sync generator accessory, an
external source of H drive, V drive, blanking and sync is required.
The
synchronizing pulse inputs must have proper width and timing of H drive, V drive,
sync and blanking pulses for proper calibration at the pattern generator section.
Pulse proportions should be as outlined on table 6-3 for the scan rate in use. It is
convenient to have H drive and V drive available for oscilloscope sync purposes. If
H drive is not available, the oscilloscope could be synchronized from blanking.
However this is not as desirable as H drive due to the absence of H blanking pulses
during the V blanking interval.
(2) Set oscilloscope channel 1 input amplitude sensitivity at 0.5v per division, direct coupled, unless
otherwise stated.
(3) Controls are located on the front panel and on circuit cards inside the unit. The circuit card name and
location of the control on the card is given for each control located on a circuit card.
(4) Set oscilloscope sync on external, negative slope (-), ac coupled, unless otherwise noted.
(5) Unless otherwise noted, the video level control at the front panel should be set at 10 (maximum
clockwise), output signal at video composite output connector and pattern polarity switch in white
position.
6-29
