10.
11.
12.
13.
12. 10
Standard Adjustment (SN 2728A and Above)
If the difference between reading and reading is greater
than 1
the A22 10 MHz Frequency Standard has not
achieved its specified aging rate; the spectrum analyzer should
remain powered (not in STANDBY) and undisturbed for an
additional 24-hour interval. Then, repeat steps 3 through 7,
recording the frequency of the 10 MHz Frequency Standard at the
end of each 24-hour interval, until the specified aging rate of 1
mHz/day
is achieved.
Reading
Reading
Reading
Reading
Reading
Position the spectrum analyzer on its right side as shown in
Figure 3-54, and remove the bottom cover. Typically, the
frequency of the A22 10 MHz Frequency Standard will shift
slightly when the spectrum analyzer is reoriented. Record this
shifted frequency of
the
A22 10 MHz Frequency Standard.
Reading
Subtract the shifted frequency reading in step 11 from the
last recorded frequency in step 10. This gives the frequency
correction factor needed to adjust the A22 10 MHz Frequency
Standard.
Frequency Correction Factor:
On the Frequency Counter, select a 1 second gate time by pressing
1
The Frequency Counter should now
display the difference between the frequency of the INPUT A
signal and 10.0 MHz with a resolution of 0.01 Hz (10
Do not use a metal adjustment tool to tune an oven-controlled
crystal oscillator (OCXO). The metal will conduct heat away from the
oscillator circuit, shifting the operating conditions.
14. Use a nonconductive adjustment tool to adjust
the
FREQ
ADJ capacitor
on
the
10 MHz Quartz Crystal Oscillator for
a Frequency Counter indication of 0.00 Hz. Refer to Figure 3-55
for the location of the
10 MHz Quartz Crystal Oscillator.
Adjustments
