If a receiver mixes a 13.8 MHz VFO with a 14.255 MHz receive signal to produce a 455 kHz intermediate frequency signal, what type of interference will a 13.345 MHz signal produce in the receiver?

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In a superheterodyne receiver, the local oscillator mixed with a received RF signal produces the intermediate frequency (IF). Any signal that lies on the opposite side of the LO by the same IF will also produce the same IF when mixed, creating image interference. Here, the LO is 13.8 MHz and the desired signal is 14.255 MHz, giving an IF of 0.455 MHz (14.255 − 13.8 = 0.455). The image frequency is the frequency on the other side of the LO that also yields this IF: 13.8 − 0.455 = 13.345 MHz. A signal at 13.345 MHz would mix with the 13.8 MHz LO to produce 0.455 MHz, the same IF as the desired signal, causing image interference in the receiver. This type of interference is called an image response.