Subelement F: Receivers— Topic 50: Receiver Performance
Question 3-50F4
Element 3 (GROL)What is cross-modulation interference?
Explanation
Cross-modulation interference occurs when a strong, unwanted radio signal enters a receiver along with a desired signal. Due to non-linearities in the receiver's RF amplifier stage, the modulation (e.g., audio or data) of the strong, unwanted signal is inadvertently transferred onto the carrier of the desired signal. The operator then hears the desired station, but with the superimposed modulation from the interfering signal, making it difficult to understand.
A) This describes general interference, not the specific mechanism of cross-modulation where one signal's *modulation* is transferred to another.
B) Audio rectification is a different phenomenon where strong RF signals are directly converted into audible frequencies by non-linear components, not the transfer of modulation between two distinct RF carriers.
D) Harmonic distortion refers to the generation of spurious signals at integer multiples of a transmitted frequency, which is a characteristic of a single transmitter's output, not an interaction between two signals in a receiver.
Related Questions
3-50F2 How can ferrite beads be used to suppress ignition noise? Install them:3-50F3 What is the term used to refer to the condition where the signals from a very strong station are superimposed on other signals being received?3-50F5 In Figure 3F15 at what point in the circuit (labeled 1 through 4) could a DC voltmeter be used to monitor signal strength?3-50F6 Pulse type interference to automobile radio receivers that appears related to the speed of the engine can often be reduced by:3-51G1 What class of amplifier is distinguished by the presence of output throughout the entire signal cycle and the input never goes into the cutoff region?