Offline Tool
Horizon & Line of Sight
Radio horizon and line-of-sight distance estimator. Flat-earth formula only — no mountains. For terrain path between two GPS points, use HeyWhatsThat Path Profiler (links).
Radio horizon distance from antenna height in feet. Works offline after your first visit.
Radio horizon and line-of-sight distance estimator. Flat-earth formula only — no mountains. For terrain path between two GPS points, use HeyWhatsThat Path Profiler (links).
Approximate line-of-sight limit for VHF/UHF — higher antenna extends usable range.
KI4TQN is a ham radio, GMRS, and emergency communications hub from East Tennessee — free tools, local reference data, YouTube-aligned guides, and consulting for property owners. Use this map to find your lane.
Pick a path: FCC-licensed GMRS, ham exam study, FRS, Meshtastic, just licensed, emcomm volunteer, or property owner.
113 offline browser tools plus step-by-step deployment workflows. Install the site as a PWA for field use.
Tri-Cities, Erwin / Unicoi (I-26), NETNRC linked repeaters, nets, HF listening, go-bag sheets, and ARES/RACES context.
Blog, videos, downloads, antenna reference, and curated radio links — tied to the YouTube channel.
Paid emergency communications consulting for estates, ranches, and remote properties — plus contact and newsletter.