Motorola ASTRO MT 1500, Service Manual, Page: 425 / 817

Chapter 7.4.4 700/800 MHz Troubleshooting Waveforms
7.4.1 Introduction
This chapter contains images of waveforms that might be useful in verifying operation of certain parts
of the circuitry. These waveforms are for reference only; the actual data depicted will vary depending
upon operating conditions. This manual is to be used in conjunction with the ASTRO XTS 2500
Digital Portable Radios Basic Service Manual (Motorola part number 68P81094C09), which uses the
pass/fail service approach to radio problems.
7.4.2 List of Waveforms
Table 7.4-1 lists each waveform and the page on which the waveform can be found.
Table 7.4-1. List of Waveforms
Waveform Page No. Waveform Page No.
Antenna Input 7.4-6 Low-Noise Amplifier Output 7.4-29
TX Signal at Harmonic Filter Input 7.4-7 Preselector 2 Output 7.4-30
Coupler RF Out 7.4-8 Mixer Out (IF) 7.4-31
TX Signal at PA 7.4-9 Crystal Filter Out 7.4-32
Coupler RF Feedback to PCIC 7.4-10 Abacus Analog 3V 7.4-33
PCIC Control Voltage 7.4-11 2nd LO Control Voltage 7.4-34
TX LO 7.4-12 2nd LO VCO Buffer Output 7.4-35
Higher Level Voltage Multiplier 7.4-13 Abacus Digital 3V 7.4-37
Superfilter Output 7.4-14 TX Audio 1 kHz Tone 7.4-38
TRB 7.4-15 16.8 MHz Buffer Input and Output 7.4-39
Prescalar Input to FracN Synthesizer 7.4-16 32.768 kHz Clock Outputs 7.4-40
Reference Crystal Output 7.4-17 SPI B Data 7.4-41
Mod In 7.4-18 RX Serial Audio Port (SAP) 7.4-42
1st LO Control Voltage 7.4-19 SPI Data 7.4-43
VCO Output 7.4-20 SPI CLK 7.4-44
VCO RX LO 7.4-21 Universal Chip Select 7.4-45
Frequency Out (16.8 MHz) 7.4-22 Abacus Chip Select 7.4-46
RX RF Input at Antenna Switch 7.4-23 RX SSI Data 7.4-47
Antenna Switch Bias 7.4-24 RX SSI Clock 7.4-48
Preselector Tuning Voltage 7.4-25 RX SSI Frame Sync 7.4-49
RX RF Input after Antenna Switch 7.4-26 RX SSI Sync B 7.4-50
Analog 5V 7.4-27
Preselector 1 Output 7.4-28