DIY 300 to 75 Ohm TV Antenna Coaxial Baluns

Here are 2 sites I found with information on how to make Television Baluns.
However, depending on your situation though, You might just go to the Deseret Industries and pick a professionally made Balun for 50¢.

Step 1: Find Parts and Start DIYing

The websites I have found so far are below.

http://homepage.mac.com/kenwetzel/Low_Loss_Balun.htm
http://flynwill.rosshay.com/Electronics/antIso/

This site has the most information and schematics
http://antiqueradios.com/forums/viewtopic.php?f=2&t=171510&start=40

Have fun DoInstructibleYourselfing.