Field Guide · organization

Also known as: RadioReference, RR

RadioReference is the largest community-maintained database of radio systems — frequencies, trunked-system types, control channels, and talkgroups, catalogued by location. It is the usual first stop when deciding what to monitor.1

RadioReferencecommunity DB control channel +talkgroup list your scanner /GopherTrunk config look up local systems → import rather than discover from scratch
Operators look up local systems on RadioReference and import the control-channel and talkgroup details into their scanner.

Overview

RadioReference.com, launched in the early 2000s, is a community website combining a large, structured database (often abbreviated RRDB) with an active discussion forum and a network of live audio feeds. The database is crowdsourced and moderated: hobbyists submit and verify the frequencies, trunked-radio system parameters, and talkgroup assignments for their areas, and the result is by far the most comprehensive public catalogue of who transmits where, especially across the United States and Canada with growing international coverage. For a P25 or other trunked system, a database entry typically lists the site frequencies, which channel is the control channel, the system’s identifiers (WACN and system ID for P25), and a decoded list of talkgroups with human-readable labels — the difference between hearing “talkgroup 4128” and knowing it is “City Fire Dispatch”.

Much of the database’s depth exists because it complements decoding rather than replacing it. Someone with an SDR and a decoder first captures a system’s raw parameters and talkgroup activity, then contributes them back so the next person can simply look them up. Premium content sits behind a paid subscription, which funds the infrastructure. The site also hosts the live audio feeds that populate scanner-streaming apps, and its forums are a long-running knowledge base for identifying unfamiliar signals. RadioReference is a community reference, not a regulator — the underlying spectrum is allocated by bodies like the FCC — but for practical “what should I tune to and what will I hear” questions it is the definitive starting point.

Relevance to SDR

For an SDR trunk-tracker, RadioReference collapses the hardest part of getting started. In most populated areas the local systems are already documented, so instead of blindly searching for a control channel and reverse-engineering an unlabelled talkgroup list, you can look up a system’s control-channel frequency and its talkgroup map and be listening to identified traffic within minutes. That head start is especially valuable for trunked systems, where you must know the control channel before the decoder can follow voice grants at all.

GopherTrunk can import RadioReference system details directly, turning a database entry into a working configuration. The relationship is genuinely two-way: GopherTrunk (like any decoder) is also a tool for discovery, surfacing the control channel, system ID, and active talkgroups of a system that the operator can then verify and submit back to the database. See the finding & identifying systems lesson for how to combine RadioReference lookups with on-air discovery.

Gotchas when consuming RadioReference data

Three quirks of RadioReference’s exports and API have each cost an importer real debugging time:

  • Sentinel expiry strings. Feed Provider and Admin accounts carry premium access, but the API’s getUserData returns no expiry date for them — instead the literal string Never - Feed Provider (or Never - Admin). A subscription check that only parses real dates reads that as “no active premium subscription” even though the login succeeded (#723).
  • PDF text encoding varies by vintage. Older RR PDFs use a font subset that shifts glyphs 27 below real ASCII, so extracted text needs a +27 un-shift — but modern PDF libraries decode newer RR PDFs via the font’s CMap and return already-correct UTF-8, which an unconditional un-shift then corrupts (S→n, M→h). The reliable discriminator is sniffing for anchor strings like System Name or Sites and Frequencies, which only survive in already-decoded text (#271).
  • The parenthesised alt-SiteID is hex. In site rows like 2-010 (2-A), the value in parentheses is the hexadecimal form of the decimal SiteID (010 ↔ A). An all-digits pattern silently fails on sites 010–015 — and worse than skipping them, the unmatched rows can be folded into the previous site’s channel list as continuation lines (#278).

Sources

  1. RadioReference.com — the official RadioReference site, the community database of radio systems, frequencies, and talkgroups, plus its forums and live feeds. ↩

See also

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