Vectronics VEC-221K - Manual (Page 7)

VEC-221K Instruction Manual CW Memory Keyer Kit
3
lead and pad for about one second (count "one-thousand-one") before feeding
solder to the connection. Surfaces must become hot enough for solder to flow
smoothly. Feed solder to the opposite side of the lead from your iron tip--solder
will wick around the lead toward the tip, wetting all exposed surfaces. Apply
solder sparingly, and do not touch solder directly to the hot iron tip to promote
rapid melting.
Desoldering Tips: If you make a mistake and need to remove a part, follow
these instructions carefully! First, grasp the component with a pair of hemostats
or needle-nose pliers. Heat the pad beneath the lead you intend to extract, and
pull gently. The lead should come out. Repeat for the other lead. Solder may
fill in behind the lead as you extract it--especially if you are working on a
double-sided board with plate-through holes. Should this happen, try heating the
pad again and inserting a common pin into the hole. Solder won't stick to the
pin's chromium plating. When the pad cools, remove the pin and insert the
correct component. For ICs or multi-pin parts, use desoldering braid to remove
excess solder before attempting to extract the part. Alternatively, a low-cost
vacuum-bulb or spring-loaded solder sucker may be used. Parts damaged or
severely overheated during extraction should be replaced rather than reinstalled.
Work Habits: Kit construction requires the ability to follow detailed
instructions and, in many cases, to perform new and unfamiliar tasks. To avoid
making needless mistakes, work for short periods when you're fresh and alert.
Recreational construction projects are more informative and more fun when you
take your time. Enjoy!
Sorting and Reading Resistors: The electrical value of resistors is indicated by
a color code (shown below). You don't have to memorize this code to work with
resistors, but you do need to understand how it works:
1st Digit
2nd Digit
Multiplier
Tolerence
Black = 0 (tens)
Brown = 1 (hundreds)
Red = 2 (K)
Orange = 3 (10K)
Yellow = 4 (100K)
Green = 5 (1Meg) Blue = 6
Violet = 7
Gray = 8
White = 9
Silver = 10%
Gold = 5%
Resistor Color Code
(gold or silver)
When you look at a resistor, check its multiplier code first. Any resistor with a
black multiplier band falls between 10 and 99 ohms in value. Brown designates
a value between 100 and 999 ohms. Red indicates a value from 1000 to 9999