20
Chapter 2
Test Descriptions
10 MHz Out Frequency Reference Adjustment
Step 1. Note Counter Reading 1 for the 10 MHz Reference Accuracy Test and
calculate the actual error in Hertz.
Actual Error = 10 MHz - Counter Reading 1
Step 2. With the actual error calculated, determine which DAC setting to adjust
from the table below.
Example 2-1
Standard NFA Actual Error
If a standard NFA Actual Error = 10,000,000 Hz - 10,000,012 Hz
the error is -12 Hz
From Table 2-4, the DAC setting must be decremented by 1 coarse
setting and 5 fine settings giving an approximate -12 Hz adjustment.
Therefore, if the original settings were, for example, Coarse = 127 and
Fine = 136, then the new settings after adjustment are Coarse = 126,
Fine = 131.
NOTE
A negative error value decrements
[
⇓
]
, while a positive error value
increments
[
⇑
]
.
Step 3. Access the
Service
menus
Time Base
sub-menu and press the
System
key.
Then press the
More
,
More
and
Service
menu keys. Enter the service
password
-2010
, press
Enter
, then press
Service
and
Time Base
.
Decrement
[
⇓
]
the NFAs DAC settings by pressing
Coarse
once and
Fine
five times.
OR
You can type in the new value on the numeric keypad and then press
Enter.
Table 2-4
DAC setting adjustments
Control Setting
Standard Step Size (Hz)
Option 1D5 Step Size (Hz)
Coarse
≈
7 Hz
≈
0.1 Hz
Fine
≈
1 Hz
≈
0.0015 Hz
Summary of Contents for N8972A
Page 9: ...ix Declaration of Conformity N8972A ...
Page 10: ...x Declaration of Conformity N8973A ...
Page 11: ...xi Declaration of Conformity N8974A ...
Page 12: ...xii Declaration of Conformity N8975A ...
Page 19: ...Contents xix ...
Page 20: ...xx Contents ...
Page 108: ...88 Chapter2 Test Descriptions Measurement Jitter ...
Page 124: ...104 Chapter3 Technical Specifications General Specifications ...
Page 136: ...116 AppendixA Model N8972A Test Records Measurement Jitter Test Record ...
Page 148: ...128 AppendixB Model N8973A Test Records Measurement Jitter Test Record ...
Page 160: ...140 AppendixC Model N8974A Test Records Measurement Jitter Test Record ...
Page 174: ...154 AppendixD Model N8975A Test Records Measurement Jitter Test Record ...