The sheet of morse code means the following...
Install Red Alert then, when the game loads, hold shift & left-click on the speaker located at the top right hand corner.

Tesla Tanks in Skirmish:
When you enter Red Alert, click on the New Missions bar. Then, click on the mission The Legacy Of Tesla. Build all the required
buildings until you can build the Tesla Tank. Then abort the mission. Now click on Multi-player Games. Select Skirmish Mode.
After you start a game, you should be able to build Tesla Tanks.

Cedrych Chan and.Stephen Hollywood