Operating instructions

BK RADIO Page 5-1
SECTION V
MAINTENANCE
5.1 INTRODUCTION
This section contains test and alignment procedures for an operational BK Radio DMH APCO
Project 25 digital mobile radio. This section also contains disassembly and assembly
procedures. An understanding of the theory of operation is recommended before maintenance
is attempted.
5.2 TEST EQUIPMENT REQUIRED
A. RF Signal Generator HP8640 or equivalent
B. Distortion Analyzer HP334A or equivalent
C. Power Meter HP435B with 30 dB pad or equivalent
D. Service Monitor HP8920A Service Monitor or equivalent
E. Digital Multimeter Fluke 8012A or equivalent
F. Computer IBM PC or compatible, with an RS-232 serial port
LAA 0725 programming cable
DMH Editor Software
G. DMH Tool/Cable Kit LAA 0621, P/N 050-03152-0000
5.3 OVERHAUL
5.3.1 ACCESSORIES
This section contains instructions to assist in determining, by inspection, the condition of DMH
assemblies. Defects resulting from wear, physical damage, deterioration, or other causes can
be found by these inspection procedures. To aid inspection, detailed procedures are arranged in
alphabetical order.
A. Capacitors, Fixed
Inspect capacitors for case damage, body damage, and cracked, broken, or charred
insulation. Check for loose, broken, or corroded terminal studs, lugs, or leads. Inspect for
loose, broken, or improperly soldered connections. On chip caps be especially alert for
hairline cracks in the body and broken terminations.
B. Capacitors, Variable
Inspect trimmers for chipped and cracked bodies, damaged dielectrics, and damaged
contacts.