Updated: Dec 9, 2025 | Source: 2022-2026 Question Pool | Topic: T2B
T2B12T2B

What is the purpose of the color code used on DMR repeater systems?

Deep Dive: T2B12

The correct answer is A: Must match the repeater color code for access. The color code in DMR (Digital Mobile Radio) repeater systems is a numeric identifier (0-15) that must match between your radio and the repeater for you to access the repeater. It's a form of access control. Each DMR repeater is configured with a specific color code. Your radio must be programmed with the same color code to communicate through that repeater. If your color code doesn't match, the repeater will reject your transmissions even if you're on the correct frequency and have the right talkgroup programmed. The color code is separate from the talkgroup ID - you need both to be correct.

Why Other Answers Are Wrong

Option B: Incorrect. The color code doesn't define frequency pairs. Frequency pairs are determined by the repeater's configuration, not the color code. Option C: Incorrect. The color code doesn't identify the codec. DMR uses a standard codec regardless of color code. Option D: Incorrect. The color code isn't about signal level requirements. It's an access control identifier.

Exam Tip

DMR color code = Must match for access. Remember: The color code must match between your radio and the repeater. It's an access control feature, not related to frequency or signal strength.

Memory Aid

**C**olor **C**ode = **C**ontrol **C**onnection (think 'CC = CC' = Control Connection, must match)

Real-World Example

You want to use a DMR repeater that requires color code 1. You program your radio with color code 1, the correct frequency, and the talkgroup ID. When you transmit, the repeater accepts your signal because the color code matches. If you had programmed color code 2 instead, the repeater would reject your transmissions even though everything else is correct.

Source & Coverage

Question Pool: 2022-2026 Question Pool

Subelement: T2B

Reference: FCC Part 97.205

Key Concepts

DMR Color code Repeater access Digital radio

Verified Content

Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T2B topic.