Filter
Top Products
11. 10 MHz Reference Adjustment-OCXO (Non-Option 103)
b. Allow the spectrum analyzer to remain powered on continuously for at least 24 hours
to ensure that the A21 OCXO temperature and frequency stabilize.
Note
If the reference is set to
10
MHz EXT , press 10
MHz
INT
. Allow the 24 hour
warmup for the OCXO before continuing. When the 10 MHz reference is set
to 10 MHz EXT , the OCXO is not operating or warmed up.
2.
Set the frequency counter controls as follows:
3.
Function/data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FREQ A
Input A:
XlOAttenuator...................................................
OFF
AC................................................. OFF(DC coupled)
50
%Z
. . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . OFF (1 MR input impedance)
AutoTrigger........................................................
ON
100 kHz filter A . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFF
INT/EXT switch (rear panel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EXT
Select a 1 second gate time on the HP
5334A/B
frequency counter by pressing
(GATE], 1, [TIME).
4.
To offset the displayed frequency by -10.0 MHz, press MATH (SELECT/ENTER),
(CHX/EEX),
10,
(CHS/EEX),
6, (SELECT/ENTER), (SELECT/ENTER). The frequency counter should now
display the difference between the frequency of the INPUT A signal and 10.0 MHz with a
displayed resolution of 0.010 Hz (10 MHz).
5.
Locate the FREQ ADJ control on the spectrum analyzer. This control is accessible
through the center deck of the spectrum analyzer. See Figure 2-19.
6.
7.
Remove the dust-cap screw.
Use a nonconductive adjustment tool to adjust the FREQ ADJ control on the A21 OCXO
for a frequency counter reading of 0.00 Hz.
8.
9.
10.
On the HP
5334A/B
frequency counter, select a lo-second gate time by pressing
[-TIME),
10, (GATE). The frequency counter should now display the difference
between the frequency of the INPUT A signal and 10.0 MHz with a resolution of 0.001 Hz
(1
mHz).
Wait at least two gate periods for the frequency counter to stabilize, then adjust the
FREQ ADJ control on A21 OCXO for a stable frequency counter reading of 0.000 Hz
kO.010 Hz.
Replace the dust-cap screw to A21 OCXO.
c. Connect the frequency standard to the frequency counter rear panel
TIMEBASE
IN/OUT connector.
d. Connect a BNC cable between the spectrum analyzer rear panel 10 MHz REF
IN/OUT connector and INPUT A on the frequency counter.
2-50 Adjustment Procedures