Radioreference

RadioReference.com maintains a database of identified frequencies and trunked radio systems, searchable by state, metro area or zip code, described on the homepage as covering 226K+ identified frequencies and 7,400+ trunked radio systems, with 59 database updates in the past 24 hours. It also runs forums, a contributor wiki, and Live Audio feeds browsable by feed, location, or dashboard, plus the related Broadcastify live-audio network and Incident Source dispatch alerts.

RadioReference Premium is priced at $15 for 6 months, $30 for 1 year, or $60 for 2 years, and the homepage states 74,286 current premium subscribers.

Its ads.txt file lists 24 ad system lines, made up of 2 direct entries and 22 reseller entries.