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Table 3-25. Numbered Error Messages (14 of 17)
16
Detector Constant > 10 V/Rad. The measured Phase Detector Constant exceeded the
system's 10 V limit.
Action: Observe the beatnote on the HP 3561A display or with an oscilloscope
connected to the AUX MONITOR port on the HP 11848A. Verify that the beatnote
amplitude is correct for the signal level at the R input port on the HP 11848A. Figure 3-
39 shows the relationship between the beatnote level and the level at the R port. If
necessary, decrease the signal level at the R port.
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R PORT SIGNAL LEVEL CdBm)
Figure 3-39. Beatnote Level Relative to the Signal Level at the R Port.
1 7
Measured Tuning Range of VCO is less than 0.2 Hz. The system was probably
unable to cause a beatnote.
The Tuning Range of the VCO is measured in this case as:
2 x Entered Voltage Range of VCO x Measured VCO Tuning Constant
Action: If the expected tuning range of the VCO source is much larger than 0.2 Hz:
1. Check the Tune Voltage cable connection.
2. Verify that the VCO source's tuning capability is enabled.
3. Verify the VCO's tuning response by performing the procedure provided in
Estimating the Tuning Constant in Chapter 3 of this manual.
4. Perform the procedure for adjusting the beatnote frequency to within 10% of the
Peak Tuning Range (PTR) set for the measurement. (The procedure for adjusting
the beatnote is provided in the Checking the Beatnote portion of each measurement
example in Chapter 3 of this manual.
If the expected tuning range of the VCO source is near 0.2 Hz:
1. Increase the tuning range, if possible, by increasing the Voltage Tune Range value
entered for the measurement.
3-134
Signal Source Applications
rev.l2JUL88
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