{"query": "GPS (UHF) — a constellation of clocks at 19 centimeters", "count": 15, "results": [{"id": "card_n_e8186ce33d19", "title": "GPS (UHF) — a constellation of clocks at 19 centimeters", "shelf": "science", "surface": "secular", "snippet": "L1 = 154 × 10.23 MHz = 1575.42 MHz EXACTLY — the whole system is integer multiples of\none 10.23 MHz atomic clock; sealed, with the 19 cm wavelength: https://narrowhighway.com/s/d6211f4efb2518c6de145de", "authority_tier": "engine_derived", "source": "Concordance assay — 2026-07-09", "generated": false}, {"id": "card_c_b781ac5089cc", "title": "GPS (UHF) — a constellation of clocks at 19  ↔ The two clocks — quartz, cesium, and the sec", "shelf": "connections", "surface": null, "snippet": "the whole system is integer multiples of one 10.23 MHz atomic clock  — a concord the card itself states; mined + verified.", "authority_tier": "engine_derived", "source": "Concordance miner — 2026-07-11", "generated": false}, {"id": "card_c_6a51e8983d6b", "title": "The radio spectrum — one law from the cavity ↔ GPS (UHF) — a constellation of clocks at 19 ", "shelf": "connections", "surface": null, "snippet": "GPS L1 as exactly 154 × 10.23 MHz with its 19 cm wave  — a concord the card itself states; mined + verified.", "authority_tier": "engine_derived", "source": "Concordance miner — 2026-07-11", "generated": false}, {"id": "card_c_fd4492f4b6a5", "title": "GPS (UHF) — a constellation of clocks at 19  ↔ Microwave (WiFi, ovens) — 12 centimeters and", "shelf": "connections", "surface": null, "snippet": "sealed, with the 19 cm wavelength: https://narrowhighway.com/s/d6211f4efb2518c6de145decf57f27b131a01c24ce7841853f395b7bc986c323  — a concord the card itself states; mined + verified.", "authority_tier": "engine_derived", "source": "Concordance miner — 2026-07-11", "generated": false}, {"id": "card_c_499ed17c0be2", "title": "GPS (UHF) — a constellation of clocks at 19  ↔ The radio spectrum — one law from the cavity", "shelf": "connections", "surface": null, "snippet": "sealed, with the 19 cm wavelength: https://narrowhighway.com/s/d6211f4efb2518c6de145decf57f27b131a01c24ce7841853f395b7bc986c323  — a concord the card itself states; mined + verified.", "authority_tier": "engine_derived", "source": "Concordance miner — 2026-07-11", "generated": false}, {"id": "card_src_word_uhf", "title": "uhf", "shelf": "dictionary", "surface": "secular", "snippet": "uhf: (noun) 300 to 3000 megahertz — syn: ultrahigh frequency", "authority_tier": "reference", "source": "WordNet 3.0, Princeton University (WordNet License)", "generated": false}, {"id": "card_c_2b9132eec485", "title": "GPS (UHF) instantiates the spectrum walk", "shelf": "connections", "surface": null, "snippet": "One band of the sealed spectrum walk.", "authority_tier": "engine_derived", "source": "Concordance assay — 2026-07-09", "generated": false}, {"id": "card_comms_ham_bands", "title": "The common ham bands — where to find people", "shelf": "communications", "surface": "secular", "snippet": "Key US amateur bands (edges are FCC regulation): HF for distance — 80m 3.5–4.0 MHz (regional, night), 40m 7.0–7.3 MHz (day/night workhorse), 20m 14.0–14.35 MHz (worldwide, daytime). VHF/UHF for local/", "authority_tier": "reference", "source": "FCC Part 97 — Amateur Radio Service (U.S. regulation, public domain)", "generated": false}, {"id": "card_comms_propagation", "title": "Propagation — why range changes with band and time of day", "shelf": "communications", "surface": "secular", "snippet": "Match the band to the distance: VHF/UHF (2m/70cm, GMRS, MURS) travel LINE-OF-SIGHT — great local, blocked by hills and horizon. HF (80/40/20m) bounces off the ionosphere ('skip') to reach over the hor", "authority_tier": "reference", "source": "U.S. Army field antenna & signaling references (public domain)", "generated": false}, {"id": "card_comms_frs_gmrs", "title": "FRS & GMRS — the license-cheap family radios", "shelf": "communications", "surface": "secular", "snippet": "The 'bubble-pack' walkie-talkies use 22 shared UHF channels (462–467 MHz). FRS is LICENSE-FREE (up to 2 watts on most channels) — fine for a family within a mile or two. GMRS reaches farther (up to 50", "authority_tier": "reference", "source": "FCC Part 95 — Personal Radio Services: GMRS/FRS/MURS/CB (U.S. regulation, public domain)", "generated": false}, {"id": "card_comms_murs", "title": "MURS — five license-free VHF channels", "shelf": "communications", "surface": "secular", "snippet": "MURS is five VHF channels (151.820, 151.880, 151.940, 154.570, 154.600 MHz), license-free, up to 2 watts. VHF often reaches farther than FRS/GMRS UHF across open ground and hills. Popular for farms, p", "authority_tier": "reference", "source": "FCC Part 95 — Personal Radio Services: GMRS/FRS/MURS/CB (U.S. regulation, public domain)", "generated": false}, {"id": "card_comms_repeaters", "title": "Repeaters — how a hilltop doubles your range", "shelf": "communications", "surface": "secular", "snippet": "A repeater sits high (hilltop, tower) and re-transmits what it hears, so two low handhelds reach each other across a whole region. Your radio listens on the repeater's OUTPUT and transmits on a fixed ", "authority_tier": "reference", "source": "FCC Part 97 — Amateur Radio Service (U.S. regulation, public domain)", "generated": false}, {"id": "card_comms_antenna_basics", "title": "Antennas — the cheapest way to double your range", "shelf": "communications", "surface": "secular", "snippet": "A better antenna beats more power almost every time. Key ideas: HEIGHT wins for VHF/UHF — they go line-of-sight, so raising the antenna a few metres can double reach. Length matters: a common field an", "authority_tier": "reference", "source": "U.S. Army field antenna & signaling references (public domain)", "generated": false}, {"id": "card_comms_ham_license", "title": "Getting a ham license — the key to the long-range bands", "shelf": "communications", "surface": "secular", "snippet": "Amateur ('ham') radio reaches from across town to across the world, and is the backbone of volunteer emergency comms. Three US license classes, each a 35-question multiple-choice exam (no Morse requir", "authority_tier": "reference", "source": "FCC Part 97 — Amateur Radio Service (U.S. regulation, public domain)", "generated": false}, {"id": "card_src_word_ultrahigh_frequency", "title": "ultrahigh frequency", "shelf": "dictionary", "surface": "secular", "snippet": "ultrahigh frequency: (noun) 300 to 3000 megahertz — syn: UHF", "authority_tier": "reference", "source": "WordNet 3.0, Princeton University (WordNet License)", "generated": false}]}