FCC Element 6 – Radiotelegraph Operator License (T) Practice Test 2026 - Free Radiotelegraph Operator Questions and Study Guide

In a superheterodyne receiver, the second detector's grid circuit is typically tuned to the intermediate frequency (IF). This is a foundational principle of how superheterodyne receivers operate.

Given that the receiver is set to a frequency of 2738 kHz and has an IF of 475 kHz, the design of the receiver dictates that the second detector is tuned to the IF frequency of 475 kHz. This is because the second detector processes the signal down-converted to the intermediate frequency after mixing the incoming frequency with a local oscillator signal.

Thus, the grid circuit of the second detector is tuned to 475 kHz, which is the correct answer in this context, confirming the operation of the superheterodyne design principles.