Vectronics VEC-221K - Manual (Page 19)

VEC-221K Instruction Manual CW Memory Keyer Kit
14
Note: The IC body has a small notch, or key, molded at one end, indicating pin
1. A small dimple-like body-molding is often found adjacent to pin 1.
Some IC packages may include both key indicators.
At this point, your kit is finished and it's time to take a well-earned break! When
you come back, be prepared to give your work a close "quality control"
inspection before moving on to the testing and alignment section.
PC Board Inspection:
Before applying power to your kit, give it a thorough QC (quality control)
inspection. This will help you find inadvertent assembly errors that might
prevent the keyer from working or cause damage to sensitive parts. Follow this
procedure:
! Compare parts locations against the parts-placement diagram. Was each
part installed where it is supposed to be? Was the correct value used? Start
at one side of the board and work your way across in an organized pattern.
! Inspect the solder side of the board for cold-solder joints and solder bridges
between tracks or pads. Use a magnifying glass to obtain a clear view of the
track area. If you suspect a solder bridge, hold the board in front of a bright
light for a better view. All joints should be smooth and shiny, indicating
good solder wetting and flow. Resolder any beaded or dull-appearing
connections.
Important Note: If you find a construction error and need to remove a part or
two, it will be easier if you have the right tools. One very convenient item for
freeing soldered-in parts is a "solder sucker". This consists of a suction bulb or
a spring loaded vacuum pump that draws molten solder away from the pad and
lead. Alternatively, you may use "solder wick". If you suspect you've damaged a
component during removal, it's better to replace the part than risk reusing it!
Now that assembly and inspection is completed, you're ready to begin the testing
and alignment phase of construction.
TESTING AND ALIGNMENT
The following items will be needed for testing:
! 9-volt alkaline transistor battery.
! Keyer paddles (iambic preferred), terminated with 3.5 mm stereo plug.
Wired dot-to-tip and dash-to-ring.
! 4- to 32-ohm headphones or monitor speaker, terminated with 3.5 mm stereo
or mono plug.