Agilent Technologies 8753ES Option 011 Service Manual page 327

Node 24 2nd LO
Perform step A12 and then press
COUNTER: ANALOG BUS
This node counts the 2nd LO used by the sampler/mixer assemblies to produce the 2nd IF
of 4 kHz. As you vary the frequency, the counter reading should change to values very close
to those indicated below:
Frequency Entered
0.03 to 1 MHz
1 to 16 MHz
16 to 3,000 MHz
Node 25 PL Ref (phase lock reference)
Perform step A12 and then press
COUNTER: ANALOG BUS
This node counts the reference signal used by the phase comparator circuit on the A11
phase lock assembly. As you vary the frequency, the counter reading should change as
indicated below:
Frequency Entered
0.3 to 1 MHz
1 to 16 MHz
16 to 3,000 MHz
Node 26 Ext Ref (rear panel external reference input)
Perform step A12 and then press
The voltage level of this node indicates whether an external reference timebase is being
used:
• No external reference: about −0.9 V
• With external reference: about −0.6 V
Chapter 10
ANALOG IN
Meas
Sweep Setup CW FREQ
Counter Reading
(frequency-entered) +4 kHz
not accurate
996 kHz
ANALOG IN
Meas
CW FREQ
Sweep Setup
Counter Reading
frequency entered
not accurate
1 MHz
ANALOG IN
Meas
Service Key Menus and Error Messages
24 x1
.
25 x1
.
.
26 x1
Service Key Menus
10-37