12. 10
Standard Adjustment (SN 2728A and Above)
4. Disconnect the short jumper cable on the RF Section rear panel
from the FREQ REFERENCE INT connector. Connect this output
(FREQ REFERENCE INT) to INPUT A on the Frequency Counter.
A REF UNLOCK message should appear
on
the CRT display.
5. Set the Frequency Counter controls as follows
FUNCTION/DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FREQ A
INPUT A:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFF (DC coupled)
Z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFF (1
input impedance)
AUTO TRIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ON
100
FILTER A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFF
INT/EXT switch (rear panel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EXT
6. On the Frequency Counter, select a 10 second gate time by
pressing
10
Offset the displayed
frequency by 10.0 MHz by pressing MATH
@
ELECT
/
ENTER
]
10
6
&
ELECT
/
ENTER
) (
SELECT
/
ENTER
].
T
h
e
Frequency Counter should now display the difference between
the frequency of the INPUT A signal (A22 10 MHz Frequency
Standard) and 10.0 MHz with a displayed resolution of 1
(0.001 Hz).
7. Wait at least two gate periods for the Frequency Counter to settle,
and record the frequency of the A22 10 MHz Frequency Standard
as reading
Reading # 1:
The
Quartz Crystal Oscillator has a typical adjustment range of
10 MHz
Hz. The oscillator frequency should be within this range
after 48 hours of continuous operation.
8. Allow the spectrum analyzer to remain powered (not in
STANDBY) and undisturbed for an additional 24 hours.
9. Repeat steps 3 through 7 and record the frequency of the A22 10
MHz Frequency Standard as reading
Reading
Adjustments
