Most common intermediate frequency (IF): For broadcast receivers that tune the medium frequency (MF) band from 540 kHz to 1650 kHz, what is the most widely used IF value?

Introduction / Context:
The intermediate frequency (IF) is a critical design choice in superheterodyne receivers. The chosen IF must balance selectivity, image rejection, and ease of filter implementation.

Given Data / Assumptions:

• Receiver covers MF broadcast band: 540–1650 kHz.
• Conventional IF choices are in the 400–500 kHz range.

Concept / Approach:

The most common IF for AM broadcast receivers is 455 kHz. This value is high enough to provide good selectivity with LC filters and low enough to avoid excessive image problems within the band.

Step-by-Step Solution:

Verification / Alternative check:

Textbooks and service manuals confirm 455 kHz as the de facto standard IF for AM broadcast sets.

Why Other Options Are Wrong:

• 433 kHz and 465 kHz: occasionally used, but less standard.
• 545 kHz and 555 kHz: too close to broadcast band, risk interference.

Common Pitfalls:

• Confusing IF of AM receivers (455 kHz) with FM receivers (~10.7 MHz).

Final Answer:

455 kHz