  In this paper we show how to construct new convolutional codes from old ones
by applying the well-known techniques: puncturing, extending, expanding, direct
sum, the (u|u + v) construction and the product code construction. By applying
these methods, several new families of convolutional codes can be constructed.
As an example of code expansion, families of convolutional codes derived from
classical Bose- Chaudhuri-Hocquenghem (BCH), character codes and Melas codes
are constructed.
