In APCO, Association of Public-Safety Communications Officials 10-codes, 10-2 typically means "Signal Good" or "Receiving Well". It is used to confirm that a radio transmission is being received clearly and without interference.
Here’s how it might be used in a real-world scenario:
- Officer: "Dispatch, radio check."
- Dispatch: "Unit 32, you’re 10-2."
In this exchange, dispatch is confirming that the officer’s transmission is coming through clearly and that no communication issues are present.
The code is commonly used during radio checks, after repositioning to a new area, or following earlier communication problems to confirm that signal quality has improved.
Historical Background
The meaning of 10-2 developed alongside 10-1 within the original APCO 10-code system, forming a complementary pair for reporting radio signal quality. Early two-way radio systems were sensitive to distance, terrain, and electrical interference, making confirmation of clear reception an operational necessity.
By standardizing phrases like 10-2, agencies reduced the need for repeated explanations and minimized radio congestion on shared frequencies.
Operational Usage
In daily operations, 10-2 is typically transmitted by dispatchers but may also be used by officers to acknowledge that incoming traffic is clear. It often follows a radio check, a channel change, or a previous report of poor reception.
Situations where 10-2 is commonly used include:
- Confirming radio clarity after a 10-1 report
- Routine radio checks at the start of a shift
- Verifying signal quality in fringe coverage areas
- Testing new or replacement radio equipment
Once 10-2 is given, normal radio traffic can proceed without further clarification.
Variations And Regional Interpretation
While 10-2 is widely understood as “signal good,” some agencies interpret it more broadly to mean that both transmission and reception are acceptable. In a few jurisdictions, the code may be omitted entirely in favor of plain-language confirmation.
Because 10-codes were developed locally rather than nationally, minor differences in usage may exist between neighboring departments, particularly during multi-agency operations.
Plain-Language Alternatives
Agencies that favor plain-language communication often replace 10-2 with direct confirmations such as:
- "You’re coming in clear."
- "Loud and clear."
- "Good copy."
These alternatives are easily understood by all responding personnel and reduce confusion when working across jurisdictions.
Modern Relevance
Although many public-safety agencies now emphasize plain-language radio traffic, 10-2 remains common in informal usage and radio culture. Its simplicity and immediacy continue to make it useful during routine operations and equipment checks.
Whether expressed as a code or in plain speech, the underlying function of 10-2 remains the same: confirming that communication is clear and reliable.
Related 10-Codes
Codes frequently referenced alongside 10-2 include 10-1 (signal weak), 10-3 (stop transmitting), 10-4 (acknowledgment), and 10-8 (in service). Together, these codes help manage radio clarity, timing, and message flow.