Operating instructions

Maintenance DMH Series VHF Radio
Page 5-4 BK RADIO
5.4 DISASSEMBLY & ASSEMBLY
The DMH radio has three major assemblies which contain the following circuit boards:
• Control Head Assembly (at the front of the radio)
Switch Board
Control Board
Options Board
• Core Assembly (in the extruded housing)
System Board
RX/TX Board
VCO Board
PA Flex Circuit
• PA Assembly (in the heatsink casting)
Filter Board
PA Board
Accessory Board
5.4.1 UNIT DISASSEMBLY
A. Remove the four corner screws from the back of the heatsink casting.
B. Carefully pull the heatsink casting from the Core assembly.
C. Disconnect the two flex cables and two coaxial cables from the PA board.
NOTE: The black-end coax is the RX input to the receiver. The white-end coax is the
exciter input to the PA.
D. Place both thumbs on the back of the Core assembly and push it out of the extruded
housing.
5.4.2 CONTROL HEAD ASSEMBLY
A. Remove the PA Assembly.
B. Remove the 6 flat-head screws around the Control Head housing.
C. Carefully pull the Control Head from the Core assembly.
D. Disconnect the two flex cables from the Options board.
E. Remove the 2 flat-head screws from the audio amplifier and 2 pan-head screws that hold
the unit together.
F. Remove the audio heat sink.
G. Remove the Options board.