How is over the air access to IRLP nodes accomplished?
The correct answer is B: By using DTMF signals. Over the air access to IRLP nodes is accomplished using DTMF (Dual-Tone Multi-Frequency) signals. DTMF tones (the beeps you hear when dialing a phone) are sent over the radio to control the IRLP node. You transmit the DTMF tones, the node decodes them, and connects you to the desired IRLP reflector or node. For amateur radio operators, understanding DTMF access is essential for using IRLP (Internet Radio Linking Project) systems. DTMF is the standard control method for IRLP nodes.
Exam Tip
IRLP access = DTMF signals. Think 'I'RLP = 'I'nput 'D'TMF. Over-the-air access uses DTMF tones (like phone dialing) to control nodes. Not voice passwords, internet passwords, or CTCSS tones.
Memory Aid
"IRLP access = DTMF signals. Think 'I'RLP = 'I'nput 'D'TMF. Use DTMF tones (like phone dialing) to control nodes over the air. Standard method for IRLP node access."
Real-World Application
You want to connect to IRLP node 1234. You transmit DTMF tones '1-2-3-4' over the radio. The IRLP node receives these tones, decodes them, and connects you to that node. DTMF is reliable and works well over radio links. This is how you control IRLP nodes from your radio - no internet connection needed, just DTMF tones.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. IRLP nodes don't use voice passwords - they use DTMF tones for control. Voice wouldn't work reliably for node control.
Option C: Incorrect. Internet passwords are for computer access, not over-the-air radio access. IRLP nodes are controlled via radio using DTMF.
Option D: Incorrect. CTCSS tones are used for repeater access (to open squelch), not for IRLP node control. IRLP uses DTMF for node commands.
题目解析
The correct answer is B: By using DTMF signals. Over the air access to IRLP nodes is accomplished using DTMF (Dual-Tone Multi-Frequency) signals. DTMF tones (the beeps you hear when dialing a phone) are sent over the radio to control the IRLP node. You transmit the DTMF tones, the node decodes them, and connects you to the desired IRLP reflector or node. For amateur radio operators, understanding DTMF access is essential for using IRLP (Internet Radio Linking Project) systems. DTMF is the standard control method for IRLP nodes.
考试技巧
IRLP access = DTMF signals. Think 'I'RLP = 'I'nput 'D'TMF. Over-the-air access uses DTMF tones (like phone dialing) to control nodes. Not voice passwords, internet passwords, or CTCSS tones.
记忆口诀
IRLP access = DTMF signals. Think 'I'RLP = 'I'nput 'D'TMF. Use DTMF tones (like phone dialing) to control nodes over the air. Standard method for IRLP node access.
实际应用示例
You want to connect to IRLP node 1234. You transmit DTMF tones '1-2-3-4' over the radio. The IRLP node receives these tones, decodes them, and connects you to that node. DTMF is reliable and works well over radio links. This is how you control IRLP nodes from your radio - no internet connection needed, just DTMF tones.
错误选项分析
Option A: Incorrect. IRLP nodes don't use voice passwords - they use DTMF tones for control. Voice wouldn't work reliably for node control. Option C: Incorrect. Internet passwords are for computer access, not over-the-air radio access. IRLP nodes are controlled via radio using DTMF. Option D: Incorrect. CTCSS tones are used for repeater access (to open squelch), not for IRLP node control. IRLP uses DTMF for node commands.
知识点
IRLP access, DTMF signals, Internet linking, Node control
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.