Definition
A radio relay station that receives a microwave signal from a remote site and retransmits it onward, extending the reach of an FAA microwave communications link between facilities such as radar sites, control facilities, and navigation aids.
Plain English
A relay station that catches a microwave signal sent from a distant site and passes it along, so the signal can travel further than a single transmitter could carry it.
Context Anchor
Seen mainly in NOTAMs or FAA facility status information, not as a normal cockpit control or procedure.
Derivation
‘Repeater’ comes from the Latin ‘repetere’ — to seek again or do again. In radio, a repeater receives a signal and sends it out again, refreshed, so it can keep going.
Why Pilots Care
If an RML repeater is out of service, the radar, communications, or navigation services that depend on that link can be degraded or unavailable. A NOTAM mentioning RMLR equipment may explain why a service you expected is missing.
Analogy
It is like a relay runner passing a baton. The original signal may not be able to reach the final point by itself, so the repeater receives it and sends it onward.
Intuition Check
Do not read “repeater” as something the pilot repeats on the radio. Here, it is ground equipment that automatically relays a signal.
Example Sentence 1
A NOTAM advised that the RMLR was out of service for maintenance, which interrupted the data link from the remote radar site.
Example Sentence 2
Technicians performed a routine inspection of the RMLR located on the ridge.