There is nothing very special on downloading and unpacking the TC's sources.
We have been informed, that some MS-Internet Explorer does not keep the file and the name in synch cause the are doing an unzip while downloading but keeping the .gz at the end of the filename.
If you get a lot of errors unpacking the tarball, that might be the cause. Try another browser to download the package.
The file is tar'ed and gzip'ed, it is unpacked by running the following command, depending on the filename:
tar -xvzf filename.tar.gz |
Note that as in the very most source packages available in the Internet, the tarball will be expanded in a subdirectory newly created in the actual directory.