Japan HF overview
The eight tracked operators have seven HF transmit sites and four separate receive sites on the Bōsō Peninsula. Microwave routes connect the HF transmitters to Tokyo and cable landing stations; McKay also carries Raft's backhaul, and DRW carries Tower's.
This comparison uses Ryota's posts through August 2026 and the September MIC, ITU and FCC research. The operator reference explains the company and station identifications; the Ryota summary follows his fieldwork and successive corrections.
Japanese sites and overseas destinations
| Operator | Japanese HF sites | Foreign receivers declared in BR IFIC |
|---|---|---|
| High Bar (NLN) | JB2XH: three Chikura TX towers; Gotenyama RX | Chicago area; London; Johor Bahru |
| GT Technologies (Optiver) | JB2XI: Cosmo West | Johor Bahru |
| JOSADA (McKay) | Kanozan TX; Nuda RX; no public HF callsign in Ryota's August account | Singapore; Hong Kong |
| DATACOM (IMC) | JS2RA / JS2RB: Kubota | Kane, Illinois; Philippines |
| 4HF (Raft) | JS2SA: Cosmo East | Chicago area; London |
| Sora (Tower) | JS2SB: Kokubo | Batam; Hong Kong; Seattle |
| Ermis (AlberBlanc/FalconIon) | Shimoizumi TX; Maeda RX; callsign withheld | Johor Bahru; Manhattan, Illinois |
| NuVo (DRW) | Minamihara RX | No Japanese outbound transmitter |
The BR IFIC column contains 15 notified endpoint pairs across the cached publication history. Japanese licences list additional destinations: Optiver has Indiana and London, Raft has Singapore, and Tower has Johor and Singapore. The ITU comparison gives the source records and dates.
The overseas coordinates are useful to different degrees. NLN supplies real receive-site locations: Elburn matches its FCC installation, its UK location has planning references, and its Johor location has an antenna tower. The NLN dossier includes those references. Raft's Illinois and Ermis's Manhattan receivers also match known FCC installations. IMC's Kane and Tower's Seattle receive installations remain unidentified; their declared points are far from the known U.S. transmitter sites. Coordinate comparisons.
IMC's June 2023 modification moved part of its Kane assignments to the Philippines while other Kane assignments remained. Tower's April 2026 modification added Seattle alongside Hong Kong and Batam. These are changes in the notified destinations; the publication chronology preserves the assignment detail.
A Canadian registration, CGA984, also points from Essex County, Ontario to Chikura. Inbound record.
Domestic transport
Three relationships matter when reading the map:
- 4HF (Raft) uses JOSADA (McKay) backhaul at Cosmo East. The tower's two microwave dishes are McKay's, facing Kanozan and Maruyama; Ryota's licence inventory lists no fixed-microwave or E-band licences for 4HF. Raft site and transport.
- Sora (Tower) uses NuVo (DRW) backhaul. Its Kokubo E-band hop enters DRW's network at Mother Farm West. Tower handoff, DRW network.
- GT Technologies (Optiver) and NuVo (DRW) share the Cosmo West tower but have separate equipment paths. Optiver goes through Mother Farm East and No. 5 Inoue; DRW goes through Mother Farm West and Kyowa Bussan Ariake. Corrected site assignments.
High Bar (NLN) and JOSADA (McKay) both reach SCSK SI1 in Inzai over separate networks. NLN's two northern arms reach Ajigaura CLS, with a Nagara–SoftBank Kamogawa–Maruyama branch connecting to its southern HF network. McKay reaches Inzai through Kanozan and NTT Funaho; its westbound route extends from Tokyo through Oyama and Shizuoka to NTT West Ise Shima in Ise city. That office is separate from the three Shima CLS markers. NLN routes, McKay routes.
DATACOM (IMC) connects Kubota through Yamazaki Shoji Wakasu to Shin-Toyosu Cube. Ermis (AlberBlanc/FalconIon) has a reconstructed direct Shimoizumi–Toyosu span across the bay. The Ryota summary gives the individual routes; the MIC channel comparisons and JOSADA analysis check them against the domestic licences.
Nuvio Tech's proposed California–Japan link ends at Ermis's Maeda receiver. Its FCC exhibit supplies the site coordinate. The commercial arrangement is unknown. Application and path exhibit.
Changes visible in the latest material
| Operator | Observation or filing change |
|---|---|
| Sora (Tower) | From two towers with four arrays in November 2024 to five towers with nine mounted arrays in August 2026, plus an assembled array on the ground. Ryota marks two of the new arrays as U.S.-bound; their possible use as a horizontal pair remains his hypothesis. The ITU destination addition is Seattle. Site history. |
| JOSADA (McKay) | Kanozan's HF Yagi was mounted by February 2026. The Kanozan–Funaho–Inzai microwave extension was photographed in August. Ryota's August account still reports no full Japanese HF licence at Kanozan. Site history. |
| High Bar (NLN) | The July–August 2026 fieldwork identifies the two Ajigaura–Inzai arms and resolves the Kamogawa connection to Maruyama. Earlier Street View brackets Sawajiri's new dishes between April 2023 and April 2026. Dated observations. |
| GT Technologies (Optiver) | The saved September MIC response lists Indiana and London as well as Johor, at 5 kW, compared with Johor alone at 2 kW in Ryota's June 2025 copy. His August comparison still lists Johor alone. The amendment date and additional receiver locations are unknown. Licence comparison. |
Open questions
- Overseas receivers: locate Optiver's Indiana and London installations, IMC's Kane receiver, and Tower's declared Seattle receiver. The FCC site inventory supplies the U.S. facilities to compare.
- Nuvio and Maeda: identify Nuvio Tech's business relationship with Ermis (AlberBlanc/FalconIon) and how the proposed California path fits into that network.
- Japanese onward paths: Nuda (McKay) and Minamihara (DRW) still have unidentified backhaul. DATACOM (IMC)'s southeast E-band endpoint at Kubota is also unnamed in the August diagram.
- Altitude Line: establish whether its Asian receiving operation involves Japan. Application 0170-EX-CN-2026 adds a Kenai transmitter. The narrative describes Chicago receivers in Europe and Asia but does not identify an Alaska counterpart or name Japan.
- Takahagi: locate and identify the rooftop dish at an Akahama data centre described in an August 4, 2026 reader comment. The commenter also mentions Hawaii/Canada cable landings.
The Ryota post summary retains the dated fieldwork and diagram detail. Full English translations and the source mirror provide the underlying articles and photographs.