Tektronix SDA601, Руководство по обслуживанию

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Adjustment Procedures
4- 6 SDA 601 Serial Digital Analyzer
6. Enter a value of zero by pressing the SDA601
0/Z
key, and then
ENTER
. The
display will resemble Figure 4--5. The letter “E” may appear on the second
display line as shown, indicating VCO lock error. If the letter E is visible
(either constantly, or flashing on and off), continue with the next step; if the
“E” is
not present, note that the lower permissible value is Ø and proceed to
step
8
.
Figure 4- 5: The VCO Lock Error Indicator
7. Press and hold the " key down until the “E” disappears from the display,
then press the A key repeatedly until it returns. Adjust the setting until you
have discovered the lowest possible “no E” value. Note this value for later
use.
8. Enter a Serial Pot value of 511 by pressing
5/R
–
1/L
–
1/L
, and then
ENTER
. As
in step 6 (above), the “E” may appear on the second display line to indicate
VCO lock error. If so, continue to the next step; if not, note that the higher
permissible value is 511 and proceed to step
10 .
9.
Press and hold the A key down until the “E” disappears from the display,
then press the " key repeatedly until it returns. Adjust the setting until you
have discovered the highest possible “no E” value. Note this value.
10.
Subtract the low “no E” value from the high value, multiply the remainder
by 0.6, and add the product to the low value. The result is the appropriate
“Serial Pot” value for this SDA601.
For example, if the lowest possible value discovered in step 7 was 45,
and the highest value—from step
9
—was 492, the correct Serial Pot
value would be:
[(492
−
45)
×
0.6]
+
45
=
313.2
11.
Round your result (not the example!) from the previous step to the nearest
integer, and enter the value with the SDA601 numeric keys; press ENTER
twice to confirm the new setting. When this step is complete, the display
should again resemble Figure 4--4, with the asterisk (*) at the end of the
second line.