Quick Answer
A radio repeater can be used without a license if the transmission power remains below the Part 15 limit of 1 watt or if it's a passive repeater that only retransmits unmodulated carrier and doesn't add any modulation or data.
Understanding Local Repeater Frequencies
When using a radio repeater, it’s essential to research the local frequency to ensure compliance with regulations. Look for the repeater’s frequency, tone, and PL (tone) settings, which can be found on online directories, repeater databases, or local amateur radio clubs’ websites. For example, the Repeater Book website (repeaterbook.com) allows users to search for repeaters by location and frequency.
Accessing Public Frequencies
Some public frequencies, such as the APRS (Automatic Position Reporting System) frequencies, can be used without a license. APRS frequencies operate on 144.390 MHz, 144.450 MHz, and 144.950 MHz for packet radio, and 144.800 MHz for position reporting. These frequencies are typically used for emergency communications and are open to anyone.
Passive Repeaters and Part 15 Compliance
Passive repeaters, also known as “simple repeaters,” only retransmit unmodulated carrier signals without adding any modulation or data. To comply with Part 15 regulations, the transmission power must remain below 1 watt. When using a passive repeater, ensure that the input signal is unmodulated and within the allowed power range. Always verify the repeater’s operation and compliance with local regulations before use.
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