Vectronics VEC-1320K - Manual (Page 7)

VEC-1320K/1330K/1340K/1380K Owner's Manual
5
Cathode
Diode LED
(shorter Lead)
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-
clockwise around the device, as shown:
1 2 3 4
8 7 6 5
Installation
Key
Key
Installation
Pin Numbers
PARTS LIST
The parts list for your kit is presented in two parts. First, you'll identify and
inventory the generic parts--those items common to all VEC QPR transceiver