A4 Log Fidelity Adjustment; Procedure - HP 8560E Service Manual

Adjustment Procedures
5. DC Log Amplifier Adjustments
5. Set up an HP 3335A as follows:
Frequency .......................... .............................................. 15 MHz
Amplitude ........................ .............................................. −18 dBm
6. Press
PEAK SEARCH
7. Reduce the input power by 40 dB, to −58 dBm (use an attenuator or
a source with a good relative amplitude accuracy).
8. If the signal is lower on the screen than expected (delta marker
reads a change of greater than 40 dB, such as −41dB), then adjust
A4R544 (see <Undefined Cross-Reference>) for an even lower level
and press and
CAL
spectrum analyzer to complete the adjustment.
9. If the signal is higher on the screen than expected (delta marker
reads a change of less than 40 dB, such as reads −39 dB), then adjust
A4R544 for an even higher level signal and press
. Allow sufficient time for the spectrum analyzer to complete
IF STATE
the adjustment.
10.Repeat the adjustment and adjust current state until the delta
marker reads −40 dB ±2 dB.

A4 Log Fidelity Adjustment

This adjustment consists of adjusting A4R531 until the error is
adjusted to zero.

Procedure

1. Press to turn the spectrum analyzer off. Remove the spectrum
LINE
analyzer cover and place the spectrum analyzer in the service
position as illustrated in
page 76 for adjustment location.
2. Connect the HP 3335A 50 Ω output to the HP 8560E/EC 50 Ω input.
Press to turn the spectrum analyzer on.
LINE
3. Press ,
PRESET CAL
.
STATE
4. Set the HP 8560E/EC controls as follows:
Center frequency ............................ ................................. 15 MHz
Span .................................... ........................................................ 0
Resolution BW ........................... ..................................... 300 kHz
Reference level ........................... .................................... −10 dBm
5. Set up an HP 3335A as follows:
Frequency ............................. ........................................... 15 MHz
Amplitude ........................ .............................................. −10 dBm
82
and
MARKER DELTA
. Allow sufficient time for the
ADJ CURR IF STATE
Figure 2-6 on page
, and
IF ADJ OFF ADJ CURR IF
.
and
CAL ADJ CURR
75. See Figure 2-7 on
Chapter 2