Deep Dive: T7C04
The correct answer is C: 1:1. A reading of 1:1 on an SWR meter indicates a perfect impedance match between the antenna and feed line. SWR (Standing Wave Ratio) is the ratio of maximum to minimum voltage (or current) on a transmission line. When SWR is 1:1, there's no standing wave, meaning all power is transferred from the feed line to the antenna with no reflection. For amateur radio operators, 1:1 SWR is the ideal condition, indicating perfect impedance matching. While 1.5:1 or 2:1 is often acceptable, 1:1 is perfect. Understanding SWR readings is essential for antenna tuning and system optimization.
Why Other Answers Are Wrong
Option A (50:50): Incorrect. This isn't a valid SWR reading format. SWR is expressed as a ratio like 1:1, 2:1, etc., not as 50:50. Option B (Zero): Incorrect. SWR cannot be zero - the minimum possible SWR is 1:1, which represents a perfect match. Zero would mean no signal, which isn't possible. Option D (Full Scale): Incorrect. Full scale on an SWR meter indicates maximum SWR (poor match), not a perfect match. Full scale means high SWR and significant mismatch.
Exam Tip
Perfect match = 1:1 SWR. Think '1:1 = 'P'erfect match. The ratio 1:1 means no standing wave - all power transfers. Lower numbers are better, and 1:1 is the best possible.
Memory Aid
Perfect match = 1:1 SWR. Think '1:1 = 'O'ne to 'O'ne = 'O'ptimal match. No standing wave, all power transfers. The lower the better, and 1:1 is perfect.
Real-World Example
You're tuning your antenna and watching the SWR meter. As you adjust the antenna length, the SWR decreases from 3:1 to 2:1 to 1.5:1, and finally reaches 1:1. At 1:1, the meter shows perfect match - all your transmitter power is being transferred to the antenna with no reflection. This is the ideal condition for maximum power transfer and minimum feed line losses.
Source & Coverage
Question Pool: 2022-2026 Question Pool
Subelement: T7C
Reference: 2022-2026 Question Pool · T7 - Practical circuits
Key Concepts
Verified Content
Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T7C topic.