Question
How much must the power output of a transmitter be raised to change the S meter reading on a distant receiver from S8 to S9?
Answer Options
- A) Approximately 1.5 times
- B) Approximately 2 times
- C) Approximately 4 times
- D) Approximately 8 times
Correct Answer: C
Explanation
The standard convention for an S meter (specifically the scale from S1 through S9) is that one S unit represents a 6 \text{dB} change in signal strength. The relationship between power ratio (P_2/P_1) and the \text{dB} change (\Delta P_{\text{dB}}) is \Delta P_{\text{dB}} = 10 \log_{10}(P_2/P_1).
To increase the signal by 6 \text{dB} (which is the step from S8 to S9), the power ratio must be P_2/P_1 = 10^{(6/10)} \approx 4. Therefore, the power output of a transmitter must be raised by a factor of approximately 4 times to change the S meter reading on a distant receiver from S8 to S9.
This topic was automatically created to facilitate community discussion about this exam question. Feel free to share study tips, memory tricks, or additional explanations!