Vectronics VEC-483K - Manual (Page 2)

VEC-483K Owner’s Manual Voice Activated Tape Recorder Switch
2
! Bright Desk Lamp
! Magnifying Glass
BEFORE YOU START BUILDING
Experience shows there are four common mistakes builders make. Avoid these,
and your kit will probably work on the first try! Here's what they are:
1. Installing the Wrong Part: It always pays to double-check each step. A 1K
and a 10K resistor may look almost the same, but they may act very
differently in an electronic circuit! Same for capacitors--a device marked
102 (or .001 uF) may have very different operating characteristics from one
marked 103 (or .01uF).
2. Installing Parts Backwards: Always check the polarity of electrolytic
capacitors to make sure the positive (+) lead goes in the (+) hole on the
circuit board. ICs have a notch or dot at one end indicating the correct
direction of insertion. Always double-check--especially before applying
power to the circuit!
3. Faulty Solder Connections: Inspect for cold-solder joints and solder
bridges. Cold solder joints happen when you don't fully heat the connection--
or when metallic corrosion and oxide contaminate a component lead or pad.
Solder bridges form when a trail of excess solder shorts pads or tracks
together (see solder tips below).
4. Omitting or Misreading a Part: This is easier to do than you might think!
Always double-check to make sure you completed each step in an assembly
sequence.
Soldering Tips: Cleanliness and good heat distribution are the two secrets of
professional soldering. Before you install and solder each part, inspect leads or
pins for oxidation. If the metal surface is dull, sand with fine emery paper until
shiny. Allow the tip of your iron to contact both the 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. Keep a damp
sponge handy to wipe your soldering tip on. This removes excess solder, and
keeps the tip properly tinned. If the iron is going to sit idling for long periods,
wipe the tip, add some fresh solder, and unplug the iron.
Desoldering Tips: If you make a mistake and need to remove a part, follow
these instructions carefully! First, grasp the component with hemostats or