Agilent Technologies NFA Series Performance Verification And Calibration Manual page 34

Step 1. Note Counter Reading 1 for the 10 MHz Reference Accuracy Test and calculate the
Step 2. With the actual error calculated, determine which DAC setting to adjust from the
Table 2-4
Example 2-1
NOTE
Step 3. Access the
Test Descriptions
10 MHz Out Frequency Reference Adjustment
actual error in Hertz.
Actual Error = 10 MHz - Counter Reading 1
table below.
DAC setting adjustments
Control Setting Standard Step Size (Hz)
≈ 7 Hz
Coarse
≈ 1 Hz
Fine
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.
A negative error value decrements
menus
Service
press the More , More and
press , then press
Enter
]
⇓
[
Decrement the NFAs DAC settings by pressing
times.
You can type in the new value on the numeric keypad and then press Enter.
22
]
⇓
[
, while a positive error value increments
sub-menu and press the
Time Base
Service menu keys. Enter the service password -2010,
and
Service Time Base
OR
Option 1D5 Step Size (Hz)
≈ 0.1 Hz
≈ 0.0015 Hz
System
.
Coarse once and Fine
[ ]
⇑
.
key. Then
five
Chapter 2