Cathode
Diode
LED
(shorter Lead)
Flat Side
Transistors:
If transistors are installed incorrectly, damage may result when power is
applied. Transistors in metal cases have a small tab near the emitter lead to identify
correct positioning. Semiconductors housed in small plastic cases (TO-92) have an
easily-identified flat side to identify mounting orientation. Many specialized diodes and
low-current voltage regulators also use this type packaging. Larger plastic transistors and
voltage regulators use a case backed with a prominent metal tab to dissipate heat (T-220).
Here, orientation is indicated by the positioning of the cooling tab.
Emitter
Flat Side
Metal Tab
Metal Can Device
Plastic Device
Tab-cooled Device
Integrated Circuits:
Proper IC positioning is indicated by a dot or square marking
located on one end of the device. A corresponding mark will be 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 diagram below. Pin numbers always start at the
keyed end of the case and progress counter-clock around the device, as shown:
1 2 3 4
8 7 6 5
Installation
Key
Key
Installation
Pin Numbers
(6) Parts List:
Your kit should contain all of the parts listed below. Please identify and inventory each
item on the checklist before you start building. If any parts are missing or damaged, refer
to the manual's warranty section for replacement instructions. If you can't positively
identify an unfamiliar item on the basis of the information given, set it aside until all
other items are checked off. You may then be able to identify it by process of
elimination. Finally, your kit will go together more smoothly if parts are organized by
