JB2XI

Original: Ryota / JJ1WTL — 505733007 · Original Japanese HTML

Published: 2025-06-19T07:36:00+09:00

English translation of the archived article text. The author’s first-person observations, uncertainty and later additions are preserved; this is not the research summary. Image contents are preserved as images, not silently incorporated into the translated prose.

Following the Radio Station Information Search update at 05:20 on Thursday, June 19, I am adding another experimental HF digital fixed station.

I identify it as this station ↓, which I have been watching as ‘the log-periodic at Cosmo Classic Club’ (click to enlarge, 2.47 MB):

From the Radio Station Information Search

https://www.tele.soumu.go.jp/musen/SearchServlet?pageID=4&IT=A&DFCD=0004567854&DD=1&styleNumber=21

Image 2: 20250619mjk-call-qth.jpg

Copied below, with boundary lines in the emission/frequency/power section to make the divisions clear.

Licensee: GT Technologies Japan GK. Licensee address: *****. Station category: experimental station. Licence number: *****. Licence issued: June 16, 2025. Valid until March 31, 2027. Purpose: experiments and tests. Permitted operating hours: continuous. Communications: matters relating to experiments, tests or investigations, excluding Argos-system data transmission

and education. Correspondent: receiving equipment belonging to the licensee near Johor Bahru, Malaysia. Identification signal: JB2XI. Installation location or operating area: Transmitting station:

Minamiboso City, Chiba Prefecture. Monitoring/control station:

Overseas, overseas. Emission classes: 12K0D1D, 12K0F1D, 12K0G1D. Frequencies: 9081, 9126, 10845, 10953, 12117, 12159, 14673, 14736, 16119, 16209 kHz. Antenna power: 2 kW. Remarks: blank.

The photographed log-periodic's beam points southwest, matching the licensed counterpart.

The tower also belongs to the company.

It is used for low-latency microwave service between the cable landing station and central-Tokyo data centres, faster than fibre by the factor associated with glass's refractive index.

Comparing all stations

An update to the table in the earlier post ‘JS2SB’:

https://jj1wtl.seesaa.net/article/505386673.html (English translation)

That table is updated here.

Even if experiments can get by with shared frequencies, can they really secure ‘12 kHz × seven companies × six frequency bands × both directions’, however much the HF bands have emptied out?

Field	JS2RA	JS2RB	JS2SA	JB2XH	JS2SB	JB2XI
Operator	DATACOM SERVICES	DATACOM SERVICES	4HF	High Bar Communications	Sora Communications	GT Technologies
Location	Kubota, Sodegaura City	Kubota, Sodegaura City	Cosmo Classic Club, Minamiboso City	TX: Kawado, Chikura-cho, Point 120 m RX: Gotenyama / Takatoriyama	Kokubo, Futtsu City	Cosmo Classic Club, Minamiboso City
Licence issued	2021-09-15 → 2024-01-01*	2023-01-25 → 2024-01-01*	2023-06-07 → 2024-01-01*	2023-07-28 → 2024-01-01*	2024-10-22	2025-06-16
Valid until	2023-12-31 → 2027-03-31*	2023-12-31 → 2027-03-31*	2023-12-31 → 2027-03-31*	2023-12-31 → 2027-03-31*	2027-03-31	2027-03-31
Counterparts	Chicago, USA	Philippines	Chicago, USA; Singapore; London, UK	Johor Bahru, Malaysia; Chicago, USA†; London, UK†	Near Hong Kong (VS6); Batam, Indonesia; Johor, Malaysia	Near Johor, Malaysia
Emission			12K0A1D		10K0A1D
Emission	12K0D1D	12K0D1D	12K0D1D		10K0D1D, 10K0D7D	12K0D1D
Emission				12K0F1D	10K0F1D, 10K0F7D	12K0F1D
Emission	12K0G1D	12K0G1D	12K0G1D	12K0G1D	10K0G1D, 10K0G7D	12K0G1D
Emission			12K0K1D
Frequency (kHz)	6864	6864	6864**	6864**	6864
Frequency (kHz)	6900		6900	6900	6900
Frequency (kHz)	9081	9081	9081**	9081**	9081	9081
Frequency (kHz)	9126		9126	9126	9126	9126
Frequency (kHz)	10845	10845	10845**	10845**	10845	10845
Frequency (kHz)	10953		10953	10953	10953	10953
Frequency (kHz)	12117	12117	12117**	12117**	12117	12117
Frequency (kHz)	12159		12159	12159	12159	12159
Frequency (kHz)	14673	14673	14673**	14673**	14673	14673
Frequency (kHz)	14736		14736	14736	14736	14736
Frequency (kHz)	16119	16119	16119**	16119**	16119	16119
Frequency (kHz)	16209		16209	16209	16209	16209
Antenna power	10 kW	5 kW	3 kW	10 kW → 1.5 kW††	8 kW, 8 kW	2 kW
Antennas***	7-element low-band upper array + 10-element high-band middle array	7-element low-band upper array + 10-element high-band middle array; 5-element Yagi below on JS2RA's tower	5-element Yagi	TX: 13 elements on each of three towers; RX: 13 elements	Two ten-element arrays on each of two towers	10 elements

*: Licence renewed.

†: Additional counterpart destination.

**: Additional frequency.

††: Reduced power.

***: Log-periodic unless otherwise stated.

Receive-only operators are omitted for space.

Including these two ↓, seven companies in all:

NuVo Networks: the Minamihara log-periodic.
Ermis: the loop array at Maeda, Minamiboso City.

Why the callsign starts with JB

Because it is a telecommunications operator.

JB is assigned to telecommunications operators.

The root is the same reason amateurs once jumped from JA to JH, rather than JB.

The company already offers commercial service over its own microwave route.

All use 28M5D7W. My estimated arrangement:

[Shin-Toyosu Cube] ↔ unlicensed link ↔ [No. 5 Inoue Building, 45 mW] —6675 MHz→ / ←6835 MHz— [45 mW, Mother Farm, 6 mW] —7450 MHz→ / ←7610 MHz— [6 mW, Cosmo Classic Club, 6 mW] —7610 MHz→ / ←7450 MHz— [1.4 mW, SoftBank Maruyama International Relay Station].

Image 3: 20241128gtt-fx.jpg