4. IF Amplitude Adjustments
3. Set the spectrum analyzer controls as follows:
Center frequency ............................................. 10.7 MHz
Span ......................................................... 200kHz
Reference level ............................................... -60
dBm
Attenuator ....................................................... OdB
dB/division
..................................................
1
dB/DIV
Resolution bandwidth .......................................... 300 kHz
Videobandwidth ............................................... 100 Hz
4. On the spectrum analyzer, press
IrV1KR),
ICAL),
and IF ADJ ON OFF so OFF is underlined.
5. Set the HP 3335A controls as follows:
Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.7MHz
Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55dBm
6. Note the marker value. Ideally it should read -60
dBm
fO.l dB.
7. If the marker reads below -60.1
dBm,
rotate A4R826 CAL OSC AMPTD one-third
turn clockwise for every 0.1 dB below -60
dBm.
If the marker reads above -59.9
dBm,
rotate A4R826 CAL OSC AMPTD one-third turn counter clockwise for every 0.1
dB
above -60
dBm.
See Figure 2-8 for the location of A4R826. A change in the displayed
amplitude will not be seen until ADJ
CURE
II?
STATE is pressed.
Note
If A4R826 has inadequate range, refer to “Inadequate CAL OSC AMPTD
Range” in Chapter 9, “IF Section.”
8. Press
ADJ
CURE
IF STATE . After allowing the analyzer time to complete the
adjustments, the displayed amplitude and marker reading should change.
9. Repeat steps 7 and 8 until the marker reads -60
dBm
fO.l dB.
10. Disconnect the test cable from A5J3 and reconnect W29 to A5J3.
A5
Reference
Attenuator
Adjustment
11. Set the spectrum analyzer reference level to -60
dBm.
If markers are displayed, press
(MKR)
and
MAEEEES
OFF .
12. Set the HP 3335A
(-1
to -60
dBm.
13. Connect a BNC cable between the 50
R
output of the HP 3335A and the spectrum
analyzer INPUT
500.
14. On the spectrum analyzer, press
ICAL)
and
EEF
LVL
ADJ
. Use the front-panel knob or
step keys to place the peak of the displayed signal 3 dB to 5 dB below the reference level.
15.
Press (PEAK SEARCH) and MARKER DELTA on the spectrum analyzer. Set the spectrum
analyzer reference level to -10
dBm.
16. Change the HP 3335A
[m)
to -10
dBm.
17. Press
LCAL)
on the spectrum analyzer.
2-28 Adjustment Procedures