TB 9-6625-2233-35
b. Adjustments
(1) Position POWER switch to OFF.
(2) Remove top cover.
NOTE
Keep top cover and shield in place during this procedure except
when necessary to make an internal adjustment.
(3) Position POWER switch to ON.
(4) Press and hold (down) A2SW1 (fig. 2) and then press CALIBRATE pushbutton.
(5) Press CURSOR ⎨ pushbutton three times and observe display indication of R33,
97, 64, VSINE XXX.
(6) Set TI for 5 V p-p output at 9.8 kHz.
(7) Connect SYNC OUT output to oscilloscope Vertical 2 input.
(8) Connect audio analyzer monitor output (rear panel) to oscilloscope Vertical 1
input and set oscilloscope controls for display of peak distortion.
(9) Adjust R33 (fig. 4) until waveform peaks are clearly visible in the residue.
(10) Adjust R97 (fig. 4) until waveform peaks are symmetrical, above and below the
average value of the residue signal.
(11) Adjust R33 (fig. 4) until peaks disappear back into the residue.
(12) Observe the overall ripple in the residue in the area of the waveform zero
peaks displayed on oscilloscope and repeat (11) above.
NOTE
If the overall ripple has decreased, continue the test of (12)
above turning the CONTROL knob clockwise. If the overall
ripple has increased, continue technique of (12) above turning
CONTROL knob counterclockwise.
(13) Repeat technique of (11) and (12) above until minimum overall ripple is
displayed on oscilloscope.
(14) Connect MULTIMETER + lead to TP 10 (fig. 4) and - lead to TP 11 (fig. 4) and
adjust R64 (fig. 4) for display of <1 mV dc.
(15) Press CALIBRATE pushbutton and verify display indicates CALIBRATION OFF.
a. Performance Check
(1) Connect UNBALANCED output to multimeter input using a 50 Ω
feedthrough termination.
(2) Press pushbuttons as listed in (a) through (h) below: