Vectronics VEC-101K - Manual (Page 6)

VEC-101K Owner's Manual Shortwave Converter Kit
4
you to differentiate between the two—chokes are generally larger in diameter
and fatter at the ends than resistors. When doing your inventory, separate out
any chokes and consult the parts list for specific color-code information.
Reading Capacitors: Unlike resistors, capacitors no longer use a color code for
value identification. Instead, the value, or a 3-number code, is printed on the
body.
Multilayer
271
(270 pF)
Ceramic Discs
|
| 1uF
35V
+ -
104
Electrolytic
1 uF
10 pF = 100
100 pF = 101
1000 pF = 102
.001 uF = 102*
.01 uF = 103
.1 uF = 104
Value Code
102
(.001 uF) (.1 uF)
As with resistors, it’s helpful to sort capacitors by type, and then to arrange them
in ascending order of value. Small-value capacitors are characterized in pF (or
pico-Farads), while larger values are labeled in uF (or micro-Farads). The
transition from pF to uF occurs at 1000 pF (or .001 uF)*. Today, while most
monolithic (multilayer) and disc-ceramic capacitors are marked with a three-
number code, you may still find a .1 uF capacitor marked either “104” or “.1”.
For three digit codes, the first two digits indicate a numerical value, while the
last digit indicates a multiplier (same as resistors). The value is in pF; thus a
capacitor marked “104” is 100,000 pF, or .1 uF.
Electrolytic capacitors are always marked in uF. Electrolytics are polarized
devices and must be oriented correctly during installation. If you become
confused by markings on the case, remember the uncut negative lead is slightly
shorter than the positive lead.
Integrated Circuits: Proper IC positioning is indicated by a dot or square
marking located on one end of the device. A corresponding mark is silk-
screened on the PC board and printed on the kit’s parts-placement diagram. To
identify specific IC pin numbers for testing purposes, see the following diagram.
Pin numbers always start at the keyed end of the case and progress
counterclockwise around the device, as shown: