
Procedure
Position instrument upright as shown in Figure 3-37 and remove
top cover.
2.
Set LINE switch to ON and press
PRESET
).
7. 3 MHz Bandwidth Filter Adjustments
Frequency Zero Check
3. Connect CAL OUTPUT signal to RF INPUT
4.
Key in
5. Adjust front panel FREQ ZERO control for maximum signal
amplitude on the CRT display.
Filter Center and Symmetry Adjustments
6.
Key in
FREQUENCY
)
20
MHz,
10
1
and press LIN pushbutton. Press
LEVEL
]
and adjust reference level, using step keys and
front-panel knob to place signal peak near top CRT graticule line.
7. On the
assembly, connect crystal filter bypass networks
between the pins above
SYM,
SYM,
SYM, and
SYM.
8. Adjust
CTR for minimum amplitude signal peak. Adjust
SYM for best symmetry of signal. Repeat adjustments to
ensure that the signal is
and adjusted for best symmetry.
See Figure 3-38 for location of adjustments.
Note
You may find it helpful to widen and narrow the frequency span of
the instrument to adjust the
symmetry and centering for
each filter stage.
3
B a n d w i d t h F i l t e r
Figure 3-38.
Location of Center, Symmetry, and 10 Amplitude
Adjustments
9. Remove crystal filter bypass network near
SYM.
Adjustments 3-73
Содержание 8568B
Страница 13: ...6 7 IF Section Bottom View 6 10 Contents 7 ...
Страница 19: ......
Страница 37: ......
Страница 42: ......
Страница 48: ......
Страница 53: ......
Страница 54: ...9 RF Gain Uncertainty Test h I 1 I I I Figure 2 16 RF Gain Uncertainty Measurement 2 32 Performance Tests ...
Страница 61: ......
Страница 90: ......
Страница 100: ...Test 9 RF Gain Uncertainty Test Step 6 2nd LO Shift Min Measured Max 1 0 dB 1 0 dB 2 78 Performance Tests ...
Страница 106: ...Test 13 Average Noise Level Test 2 84 Performance Tests ...
Страница 109: ...Test 16 Residual FM Test Test 16 Residual FM Test Step 14 Residual FM IMinIMeasuredIrax Performance Tests 2 87 ...
Страница 162: ......
Страница 224: ......
Страница 268: ......
Страница 270: ......
Страница 272: ......
Страница 278: ......
Страница 307: ...w43 c c5 c4 c3 c2 Figure 6 l RF Section Top View A26 6 4 Major Assembly and Component locations ...
Страница 312: ...AlVl Figure 6 6 IF Section Front View w3 w9 Major Assembly and Component locations 6 9 ...