FCC Question Pool Review

Technician Class (Element 2) • 2022-2026

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Question T8C06

From subelement T8 - T8C

T8C06
Answer: B

How is over the air access to IRLP nodes accomplished?

ABy obtaining a password that is sent via voice to the node
BBy using DTMF signals
CBy entering the proper internet password
DBy using CTCSS tone codes

Why is this correct?

IRLP (Internet Radio Linking Project) nodes are accessed over the air by using DTMF (dual tone multi-frequency) signals - the touchtone sounds your radio keypad makes. You punch in the node number on your radio's keypad to connect to specific IRLP nodes. Voice passwords, internet passwords, and CTCSS tones are not used for IRLP node access - only the DTMF tones generated when you press numbered keys.

Memory tip

Remember the pattern: IRLP uses your existing radio interface through familiar keypad tones. Think 'touch-tone access' - the same DTMF signals used for phone systems work for IRLP networking. No special codes or internet credentials needed.

Learn more

IRLP nodes function as radio-to-internet gateways using VoIP technology to connect amateur stations worldwide. When you transmit DTMF node numbers, the IRLP system interprets these as connection commands, linking your local repeater to distant repeaters or stations. This preserves traditional amateur radio operation while extending range globally. Understanding IRLP helps you leverage internet backbone networks while maintaining RF-based access methods and amateur radio protocols.

Think about it

Why do you think IRLP was designed to use DTMF tones instead of requiring special software or internet access like some other digital modes?