HP 8924E, Assembly

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Chapter 14, Diagnostics Descriptions
Description of the Digital Assembly Diagnostics (CDMADIAG)
N:\mkt\MANUALS\HP8924C\ALR\diagnos.fb
I/Q Modulator
Q Control
Voltage This is the Qquadrature adjust signal that is derived
from the quadrature Adjust Error Voltage. IQMOD_VCQ
I/Q Modulator
LO Bias Volt-
age This point monitors the output of a DAC that tunes a
VCO inside the I/Q Modulator IC. IQMOD_VBLO
DAC Quadra-
ture Adjust
Output This point monitors the output of a DAC that adjusts
the phase of the I/Q Modulator IC to achieve quadra-
ture. IQMOD_QUAD_ADJ
I/Q Modulator
IC DI and DQ
pins These points monitor the quadrature adjust lines out of
the I/Q Modulator IC before reaching the Quadrature
Adjust circuitry. IQMOD_Di_diag
IQMOD_Dq_diag
I/Q Modulator
Ground This point measures the ground potential of the I/Q
Modulator Assembly. IQMOD_GND
Zero Power RF
Detector Offset This point measures the offset of the RF Power Detec-
tor at the zero power state. IQMOD_RF_DET_OFFSET
Table 135 Cell Site Analog
Measurement Explanation and Suggestions Measurement Point
Cell Site 1
Video DACs
Reference Volt-
age Supply This point measures the level of the reference supply for
the three Cell Site #1 video DACs. CSAN_VREF_2_S
Cell Site 2
Video DACs
Reference Volt-
age Supply This point measures the level of the reference supply for
the three Cell Site #2 video DACs. CSAN_VREF_4_S
Control DACs
Reference
Voltage Supply
Sense The +15V supply is regulated to +10V and used as a ref-
erence for the Gain DACs. This voltage is sampled
through a 1-to-2 voltage divider; so this voltage should
measure very close to +5 V. CSAN_PLUS10_REF_S
Cell Site 1 Amp
1 Gain Control These points monitor the output of the Cell Site #1 Gain
Control DAC Q and I gain control lines. CSAN_I1_GAIN_S
CSAN_Q1_GAIN_S
Table 134 I/Q Modulator (Continued)
Measurement Explanation and Suggestions Measurement Point