Ham Amateur Radio Technician Practice Exam 2026 – The Complete All-in-One Guide to Exam Success

A mixer's main function in radio communications is to combine two frequencies: the Local Oscillator (LO) frequency and the Radio Frequency (RF) input frequency. When these two frequencies are mixed, the output produces signals at two specific frequencies: the sum and the difference of the input frequencies.

If you denote the LO frequency as \( f_{LO} \) and the RF frequency as \( f_{RF} \), the mixer will generate two output frequencies:

1. \( f_{sum} = f_{LO} + f_{RF} \)

2. \( f_{difference} = f_{LO} - f_{RF} \)

This property is used in many applications, such as frequency translation in receivers, allowing for the selection and processing of different signals on various frequencies. Understanding this principle is critical for anyone studying radio frequency technologies and is a fundamental aspect of how many communication systems operate.

The other options refer to concepts that do not apply to the behavior of a mixer in this context. The average and product, integral and derivative, and square and cube do not represent the mathematical relationships established when two frequencies are mixed. Thus, the focus is on the correct understanding that mixing results in the sum and difference of the input