Matching Transformers

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Matching Transformers

If your FM receiver has a 75 ohm connection and no 300 ohm connection you will need to get what is called a "matching transformer." The purpose of this transformer is to change the impedance at a connection between the antenna and the cable or between the cable and the receiver from 300 ohms to 75 ohms thereby reducing the loss that would otherwise result from the mismatch. There are a variety of types but they look like this:

 The Twin Lead connects to the two screws at the bottom left. A short piece of coax cable with a female end on one end (to attach to the matching transformer) and bare wire at the other (to attach to the 75 ohm connection on the receiver should be used as well. Use this type of transformer if you are using a folded dipole type driven element and running coax from the antenna to the receiver. The transformer goes on the antenna and the coax fastens to the threaded end of the transformer.

 

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