Microwave routes (Ajigaura and Inzai)
Original: Ryota / JJ1WTL — 521035620 · Original Japanese HTML
Published: 2026-07-01T20:59:00+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.
News of High Bar Communications’ northward expansion has sent me off on another journey of discovery.
Desk research
Radio Station Information Search
The red annotations below are my conventional, first-pass assumptions:
Hitachinaka
The cable landing station at Ajigaura.
There are two possibilities, but I expect it to be Arteria.
(Because KDDI is also out of the picture at Chikura and Maruyama.)
Kamogawa
The obvious candidate would be Mount Kiyosumi.
Inzai
A data centre.
Probably MC Realty or COLT, particularly since they promote low latency.
Putting it on a map
Roughly, it looks like this [annotations added to OpenStreetMap].
The blue lines are the company’s new sections: the targets of this search.
If you know of a newly erected tower in any of the municipalities in these diagrams, please let me know.
It should carry two dishes, almost back to back. Alternatively, they might be piggybacking on an existing tower.
For a starting point, I will investigate what are probably the actual destinations:
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Ajigaura
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Inzai
I will look for them on the ground.
To Ajigaura
Sunday, June 28.
The weather looks unpromising, so I give up on a mountain trip and stick to the flatlands. :-)
My first visit to Ajigaura since 1992, back when there was such a thing as a departmental outing.
Tamachi 4:36 → Ueno 5:11 → Katsuta 7:05 / 7:26 → Ajigaura 7:56.
Construction of the new Haneda line.
The inbound Tokaido Main Line track will be moved towards the heavy machinery (from the background to the foreground).
Leaving Tamachi.
Ueno.
Katsuta. Here is the transfer.
‘Are you making a return trip?’ ‘There’s a day pass.’ They exchanged my ¥570 ticket for it with an additional ¥130.
So, although it says ¥1,100, it cost ¥700.
Onto the Minato Line.
That is the Ferris wheel at Hitachi Seaside Park in the distance.
Arrived at Ajigaura.
Hmm? I can already see something…
Two directions. This is it, no doubt.
KDDI
Before that, though…
First, let’s stop at KDDI. Some of the following photographs can be enlarged by clicking.
The name has not been concealed.
(The sign at SoftBank’s Maruyama International Relay Station was removed.)
- In the enclosure in front: Starlink earth stations / mobile base earth stations.
The ‘takoyaki antennas’.
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The building at the far right: Arteria.
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On the rise at the back right: our target tower. Oh… that is outside Arteria’s grounds.
Arteria
Past it, taking the path on the right towards the back.
The target tower
Successfully reached it.
In the end, I approached from the station side.
The top.
The antenna on the left as we look at it.
The beam points south-southwest. There is almost no difference in bearing between the two antennas.
For the facilities enthusiasts.
This company puts nameplates on its equipment, which is helpful.
See? Confirmed.
The rack. The main equipment is here. The fans are extremely loud.
The pole carrying the incoming fibre.
See: Arteria.
It stands on a rise beside a residential area. Let’s pan from left to right.
Time to withdraw. I use the same path in both directions: the one running into the background in the photograph immediately above.
As someone now departed used to say, ‘Watch out for brand-new service poles.’ There you go.
Measuring the bearing from the end of Ajigaura Station’s platform.
Yes: it points straight this way.
Reviewing Google Earth after getting home
There was a photograph taken during construction, at the bottom of the image.
That helps improve the estimated bearing towards the next hop.
Moving on to Inzai
A good start.
Now to identify the Inzai data centre connected to this route.
As planned…
Ajigaura 8:43 → Katsuta 9:11 / 9:58 → Tsuchiura 11:05 / 11:13 → Kashiwa 11:53 / 11:58 → Shin-Kamagaya 12:14 / 12:27 → Chiba New Town Chuo 12:38.
Ajigaura’s station building, which I had forgotten to photograph.
At the right edge, beyond the woods, is the top of our target: HBC’s tower.
This is the train I’m taking.
A boarding-station certificate.
Katsuta. I let the train terminating at Mito go and wait for the one to Tsuchiura.
Tsuchiura.
Kashiwa. A five-minute transfer!
Shin-Kamagaya. The station melody is the Fighters’ anthem.
Arrived at Chiba New Town Chuo
Looking for a data centre with dishes on top, I start searching from the nearest built-up area.
At first glance, it feels like Toyosu or Makuhari.
Towards MC Realty and COLT.
Oh? Found it!
This…
https://www.google.com/maps/@35.8093131,140.1199707,103m/data=!3m1!1e3
…is…
Neither MC Realty nor COLT.
My guess was wrong.
After some determined searching, I find that it is SCSK’s SI1.
We are looking at the south face.
Let’s check the opposite, northern side as well. Yes, antennas there too.
By stepping well back, I can just make out the antennas on both faces.
Zoomed in.
Close-ups of each antenna
South face
On the left as we look at it.
On the right as we look at it.
North face
I tried to capture a side view.
Measuring the bearings
South side
This is the link towards the Nagara station.
South-southeast.
Nagara is quite a distance away, so it is difficult to pinpoint its location from here in Inzai.
North side
This is the link towards the Ushiku station.
I judge it to be northeast.
Today’s results
The shaded areas are the next provisional search locations.
The whole picture.
Homeward, triumphant
Chiba New Town Chuo 14:27 → Mita 15:18.
Chiba New Town Chuo.
One train all the way home!
Expenses
¥2,420 — JR, Tamachi → Katsuta
¥700 — Hitachinaka Seaside Railway, Katsuta–Ajigaura return, Minato Line one-day pass
¥1,782 — JR, Katsuta → Kashiwa
¥261 — Tobu, Kashiwa → Shin-Kamagaya
¥475 — Shin-Kamagaya → Chiba New Town Chuo
¥1,151 — Hokuso / Toei, Chiba New Town Chuo → Mita
――――――――――――――――――――――――――――――――――――
¥6,789 — total
To be continued...