Deep Dive: G2E14
The correct answer is D: All these choices are correct. If you cannot decode an RTTY or other FSK signal even though it is apparently tuned in properly, the problem could be: the mark and space frequencies may be reversed, you may have selected the wrong baud rate, or you may be listening on the wrong sideband. All three are common causes of decoding problems. For amateur radio operators, checking all three helps troubleshoot FSK decoding issues. Understanding this helps when operating RTTY or other FSK modes.
Why Other Answers Are Wrong
Option A: While correct, this is incomplete. Wrong baud rate and wrong sideband can also cause problems. Option B: While correct, this is incomplete. Reversed frequencies and wrong sideband can also cause problems. Option C: While correct, this is incomplete. Reversed frequencies and wrong baud rate can also cause problems.
Exam Tip
All three can cause FSK decoding problems: reversed frequencies, wrong baud rate, wrong sideband. When all listed causes can prevent FSK decoding, 'all of the above' is usually the answer. Check all three when troubleshooting.
Memory Aid
All three can cause FSK decoding problems: Reversed frequencies, Wrong baud rate, Wrong sideband. Think 'A'll 'F'SK 'D'ecoding 'P'roblems. Check all three when troubleshooting RTTY or FSK signals.
Real-World Example
You can't decode an RTTY signal even though it's tuned in. Check: (1) Mark and space frequencies may be reversed - try reversing them, (2) Baud rate may be wrong - try different rates (45, 50, 75, 100 baud), (3) You may be on the wrong sideband - RTTY on HF typically uses LSB. All three can prevent decoding.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G2E
Reference: 2023-2027 Question Pool · G2 - Operating Procedures
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G2E topic.