Elecraft T1 Assembly Manual - Manual (Page 3)

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The color bands that indicate the value of resistors are shown in the text to help you identify the correct
part. However, it’s helpful to familiarize yourself with the color code (see Figure 1). For example, a resistor
with the color bands of brown, red, yellow, gold would be a 120K ohm, 5% resistor. This resistor will be
identified in the text as 120K ohm (brn-red-yel).
If you are in doubt about a resistor’s value, use a DMM. Do not be concerned with minor deviations from
the expected value. Typical errors on most DMMs and the tolerances of the resistors normally produce
readings that are slightly different from the values indicated by the color bands.
FIRST DIGIT
SECOND DIGIT
MULTIPLIER
Black
Brown
Red
Orange
Yellow
Green 0
1
2
3
4
5 X 1
X 10
X 100
X 10K
X 10K
X 100K
COLOR DIGIT MULTIPLIER
Blue
Violet
Gray
White
Silver
Gold 6
7
8
9
-
- X 1M
-
-
-
X 0.01
X 0.1
COLOR DIGIT MULTIPLIER
TOLERANCE:
GOLD = 5%
SILVER = 10%
Figure 1. Resistor Color Code.
Soldering and Desoldering
i
Use adequate ventilation when soldering; avoid inhaling smoke or fumes. Always wash your
hands after handling solder, as lead residue is highly toxic.
When applying solder, use the minimum amount required to surround the component lead and make good
contact with its printed-circuit pad. You don't need a "fillet" (build-up) of solder. This will avoid unwanted
solder bridges and any need to clean the PC boards.
The solder must flow onto both the component lead and its PC board pad. To ensure that both will be
heated at the same time, the tip of the iron should contact both the component lead and the PC board pad
before solder is applied.
Solder joints should be clean and shiny. If a joint appears dull or has fine cracks, it is probably cold. Cold
solder joints should be cleaned and re-soldered. First, use solder wick (desoldering braid) to remove the old
solder. Then apply fresh solder. If you have many cold solder joints, it probably indicates that your
soldering iron temperature is too low, or that the tip or solder itself is defective.