Operating instructions
DMH Series VHF Radio  Maintenance 
BK RADIO  Page 5-3 
L.  Terminal Connections Soldered 
1.  Inspect for cold-soldered or resin joints. These joints present a porous or dull, 
rough appearance. Check for strength of bond using the points of a tool. 
2.  Examine the terminals for excess solder, protrusions from the joint, pieces adhering 
to adjacent insulation, and particles lodged between joints, conductors, or other 
components. 
3.  Inspect for insufficient solder and unsoldered strands of wire protruding from 
conductor at the terminal. Check for insulation that is stripped back too far from the 
terminal. 
4.  Inspect for corrosion at the terminal. 
5.3.2 CLEANING 
A.  Using a clean, lint-free cloth lightly moistened with soap and water only, remove the 
foreign matter from the equipment case and unit front panel. Wipe dry using a clean, dry, 
lint-free cloth. 
B.  Using a hand controlled dry air jet (not more than 15psi), blow the dust from inaccessible 
areas. Care should be taken to prevent damage by the air blast. 
C.  Clean the receptacles and plugs with a hand controlled dry air jet (not more than 25psi), 
and a clean, lint-free cloth lightly moistened with soap and water only. Wipe dry with a 
clean, dry, lint-free cloth. 
5.3.3 REPAIR 
This section describes the procedure along with any special techniques for replacing damaged 
or defective components. 
A. Connectors 
When replacing a connector, refer to the appropriate PC board assembly drawing and 
follow the notes to insure correct mounting and mating of each connector. 
B. Crystal 
The use of any other than a BK Radio crystal is considered an unauthorized modification. 
C. Diodes 
Use long nose pliers as a heat sink under normal soldering conditions. Note the diode 
polarity before removal. 
D. Integrated Circuits 
Refer to Appendix A for removal and replacement instructions. 
E. Wiring/Coaxial Cable 
When repairing a wire that has broken from its terminal, remove all old solder and pieces 
of wire from the terminal, restrip the wire to the necessary length and resolder the wire to 
the terminal. Replace a damaged wire or coax with one of the same type, size, and 
length. 










