1. Where the Station Data Comes From
- Licensed Broadcast Transmitters: Every active licensed (status
LIC) record in the official FCC TV Query database across Full Power (DTV/DTS), Class A (DCA), Low Power (LPD), and Translator (LPT/DRT) services: 7,523 transmitter records covering 7,201 broadcast facilities. - 360-Degree FCC Service Contours: The FCC Media Bureau's predicted service contour data points, which provide 360 directional coverage radials (1° increments) for each transmitter computed using FCC F(50,90) propagation curves, Effective Radiated Power (ERP), and Height Above Average Terrain (HAAT).
- Virtual Channels & Network Affiliations: Virtual channel numbers come from the FCC TV Query and CDBS facility database. Network affiliations come from the FCC CDBS facility file (last published by the FCC in January 2024). Low-power and translator stations without an FCC-listed network are labeled clearly as Local / LPTV rather than guessed.
- ZIP & City Coordinates: U.S. Census Bureau 2024 Gazetteer geographic center points for 33,791 ZIP Code Tabulation Areas (ZCTAs) and 10,255 cities and towns.
2. How Each Signal Badge Is Calculated
For every ZIP code and city, we compute the great-circle distance and azimuth bearing between the location and every TV transmitter. We interpolate the station's exact FCC predicted contour reach along that radial and divide your distance by the station's FCC contour reach:
| Distance Ă· FCC Contour Reach | Signal Badge | Recommended Antenna Setup |
|---|---|---|
| Up to 50% of contour edge | ● Strong — Indoor OK | Well inside the FCC coverage contour. An indoor window or tabletop antenna works in most homes (check VHF requirements). |
| 50% – 80% of contour edge | ● Moderate — Window / High Indoor | Inside the FCC contour, mid-distance. A high 2nd-floor window facing the tower or an attic antenna gives reliable lock. |
| 80% – 100% of contour edge | ▲ Weak — Outdoor / Attic | Near the outer edge of the FCC service contour. An attic or rooftop directional antenna is recommended. |
| 100% – 125% of contour edge | ○ Fringe — Deep Outdoor | Just outside the FCC predicted contour. Requires a high rooftop directional antenna and low-noise preamplifier. |
3. What ZIP-Level Estimates Cannot Model
- Local Terrain & Obstructions: While the FCC's 360-radial contour accounts for average terrain elevation along each radial, it does not model a steep hill right behind your house, dense wet tree canopy, tall neighboring buildings, or stucco/metal siding.
- Exact Street Address: ZIP and city pages measure from the Census geographic center of that ZIP or city.
For a street-address terrain profile, you can also cross-check the FCC's DTV Reception Maps.