How may amateurs use the 219 to 220 MHz segment of 1.25 meter band?
The correct answer is D: Fixed digital message forwarding systems only. According to FCC Part 97.305, the 219-220 MHz segment of the 1.25-meter band is restricted to fixed digital message forwarding systems only. This is a specialized allocation for automated digital communications.
This narrow 1 MHz segment (219-220 MHz) is set aside specifically for digital message forwarding systems, which are automated stations that receive, store, and retransmit digital messages. These systems are often used for packet radio networks and digital messaging services. The restriction ensures that this segment remains available for its intended purpose and prevents interference from other modes like voice, video, or other digital modes. Operators must use digital modes designed for message forwarding in this segment.
Exam Tip
219-220 MHz = Digital message forwarding only. Remember: This is a very specific restriction - only fixed digital message forwarding systems. No voice, no video, no other digital modes.
Memory Aid
"**2**19-**2**20 = **D**igital **M**essage **F**orwarding (think '2-2 = DMF')"
Real-World Application
Your local amateur radio club operates a packet radio network using a digital message forwarding system. The system's frequency is 219.550 MHz, which is within the 219-220 MHz segment. This automated system receives packet messages, stores them, and forwards them to their destinations. When you send a packet message to a distant station, it goes through this forwarding system, which is exactly what this frequency segment is designed for.
FCC Part 97.305Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Spread spectrum is not permitted in the 219-220 MHz segment. This segment is specifically for fixed digital message forwarding systems.
Option B: Incorrect. Fast-scan television is not permitted in this segment. The segment is restricted to digital message forwarding systems only.
Option C: Incorrect. While emergency traffic is important, this segment is not reserved for emergency use only. It's for fixed digital message forwarding systems, which may handle emergency traffic but are not limited to it.
题目解析
The correct answer is D: Fixed digital message forwarding systems only. According to FCC Part 97.305, the 219-220 MHz segment of the 1.25-meter band is restricted to fixed digital message forwarding systems only. This is a specialized allocation for automated digital communications. This narrow 1 MHz segment (219-220 MHz) is set aside specifically for digital message forwarding systems, which are automated stations that receive, store, and retransmit digital messages. These systems are often used for packet radio networks and digital messaging services. The restriction ensures that this segment remains available for its intended purpose and prevents interference from other modes like voice, video, or other digital modes. Operators must use digital modes designed for message forwarding in this segment.
考试技巧
219-220 MHz = Digital message forwarding only. Remember: This is a very specific restriction - only fixed digital message forwarding systems. No voice, no video, no other digital modes.
记忆口诀
**2**19-**2**20 = **D**igital **M**essage **F**orwarding (think '2-2 = DMF')
实际应用示例
Your local amateur radio club operates a packet radio network using a digital message forwarding system. The system's frequency is 219.550 MHz, which is within the 219-220 MHz segment. This automated system receives packet messages, stores them, and forwards them to their destinations. When you send a packet message to a distant station, it goes through this forwarding system, which is exactly what this frequency segment is designed for.
错误选项分析
Option A: Incorrect. Spread spectrum is not permitted in the 219-220 MHz segment. This segment is specifically for fixed digital message forwarding systems. Option B: Incorrect. Fast-scan television is not permitted in this segment. The segment is restricted to digital message forwarding systems only. Option C: Incorrect. While emergency traffic is important, this segment is not reserved for emergency use only. It's for fixed digital message forwarding systems, which may handle emergency traffic but are not limited to it.
知识点
FCC Part 97.305, 1.25-meter band, 219-220 MHz, Digital message forwarding, Restricted segments
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.