Table 10-12 Unlocked Fractional N Troubleshooting Areas (08560-60069 And Above); Table 10-13 . Unlocked Fractional N Troubleshooting Areas (08560-60062 And Below) - HP 8560E Service Manual

3. Change the spectrum analyzer from the fractional N span to 0 Hz.
4. Check the frequency at A14TP1. It should equal the value found by
5. Check the tune voltage at the ungrounded end of C135.
6. Look up the expected problem area in
Table 10-12 Unlocked Fractional N Troubleshooting Areas (08560-60069 and
Above)
Measured VCO
Frequency
Relative to
Expected Value
Measured >
expected
Measured <
expected
Measured, not
oscillating
Table 10-13 Unlocked Fractional N Troubleshooting Areas (08560-60062 and
below)
Measured VCO
Frequency
Relative to
Expected
Value
Measured >
expected
Measured <
expected
Measured, not
oscillating
Chapter 10
A15 RF assembly.
pressing ,
CAL MORE 1 OF 2
the information from steps 4 and 5. Go to the appropriate
troubleshooting steps.
Less than
−4 V
VCO clamp VCO
VCO clamp Divider or
VCO clamp VCO
Less
than
−12.5 V
VCO
clamp
VCO
clamp
VCO
clamp
, , and
FREQ DIAGNOSE
Table 10-12 on page 549
Tune Voltage
About Between
−3.3 V −2 V and
+10 V
Divider or
integrator
Divider or
integrator integrator
VCO
Tune Voltage
About Between
−11 V ±10 V
VCO Divider or
integrator
Divider or Divider or
integrator integrator
VCO VCO
Synthesizer Section
Unlocked Fractional N PLL
.
RAW OSC FREQ
with
About Greater
+11 V than
+12.5 V
Divider or VCO clamp
integrator
VCO VCO clamp
VCO VCO clamp
About Greater
+11 V than +12.5
V
Divider or VCO clamp
integrator
VCO VCO clamp
VCO VCO clamp
549