Motorola Astro XTL 1500 User Manual

6815854H01-A June 15, 2005
Troubleshooting Procedures: UHF Range 2 (450–520 MHz) Band Main Board Troubleshooting 4-17
4.8 UHF Range 2 (450–520 MHz) Band Main Board Troubleshooting
This information will help you troubleshoot the RF section of the UHF Range 2 (450–520 MHz) band
XTL 1500 radio. Use this information, along with the theory of operation and troubleshooting charts,
to diagnose and isolate the cause of failures.
Prior to troubleshooting, it is important to review the theory of operation, including specific
precautions and troubleshooting methods. Because much of the radio's circuitry operates at high
frequencies, measurements must be taken very carefully. Notes and cautions are added to the text
to alert you to this need in areas of greatest sensitivity. However, the need for extreme care does
exist in all measurements and tests.
4.8.1 Display Flashes “FAIL 001”
This display indicates a synthesizer “out-of-lock” condition. The following information will help to
trouble shoot the frequency generation unit to the component level. Perform the following checks to
determine the mode of the Fail 001:
1. Determine if the “out-of-lock” condition occurs in either receive mode, transmit mode, or both.
Also, check other frequencies programmed in the unit if available.
2. To determine if the “out-of-lock” is frequency or VCO dependant, place the unit into RF TEST
Mode, as described in the ASTRO Digital XTL 1500 VHF/UHF Range 1/UHF Range 2/700–
800 MHz Mobile Radio Basic Service Manual (6815853H01) and step through each test
channel. Table 4-10 indicates the frequency and Aux logic level for each test mode channel.
In addition, Table 4-11 on page 4-18 provides information about the frequency of operation for
each VCO.
Table 4-10. Test Mode Channels UHF Range 2 (AUX 4 is not used for VCO selection in UHF)
Test
Mode
AUX (TX Logic)
TX
VCO
TX Freq
(MHz)
AUX (RX Logic)
RX
VCO
RX Freq
(MHz)
RX VCO
Freq
(MHz)1 2 3 1 2 3
Chan 1
100
Q5826450.025001Q5905450.075559.725
Chan 2
100
Q5826455.825001Q5905455.625565.275
Chan 3
100
Q5826463.675001Q5905463.625573.275
Chan 4
100
Q5826473.375110Q5903473.325582.975
Chan 5
100
Q5826484.975110Q5903484.925594.575
Chan 6
000
Q5825485.025110Q5903485.075594.725
Chan 7
000
Q5825490.825110Q5903490.875600.525
Chan 8
000
Q5825496.625010Q5901496.675606.325
Chan 9
000
Q5825508.375010Q5901508.325617.975
Chan 10
000
Q5825519.975010Q5901519.925629.575

Motorola Astro XTL 1500 Specifications

General

IP Rating	IP54
Frequency Range	136-174 MHz, 380-470 MHz, 764-870 MHz
Battery Life	Not applicable
Display	Alphanumeric
Digital Protocol	APCO Project 25 (P25)
Encryption	DES, AES
Operating Temperature	-30°C to +60°C