Vectronics VEC-820K - Manual (Page 6)

VEC - 8 2 0 K Ins tr u c ti on M an u al C W F il ter K i t
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.
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: