The Yagi on Mount Kanozan

Original: Ryota / JJ1WTL — 519927784 · Original Japanese HTML

Published: 2026-02-09T22:49:00+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.

A sequel to ‘Mid-winter antenna finding’: a new experimental station for HF digital fixed services.

AVANT 2

Sunday, February 8.

Tamachi 7:44 → Shimbashi 8:01 → Kisarazu 8:26 / 8:41 → Sanukimachi 10:00 / 10:20 → taxi → Jinyaji Temple, Mount Kanozan, 10:33. [Translator's note: the timetable is reproduced as written.]

Two weeks have passed since the previous visit, so I am going ahead despite the bad weather.

The scene on ‘Fairlady Z acceleration’ Street—a reference to the celebrated episode 104.

A thin covering of snow on the pavement.

Tamachi.

Haneda new-line construction. This must be the work that caused the recent power outage.

Departing.

Work is progressing on the trackbed where the inbound Tokaido Main Line will move.

Shimbashi.

Snow at Funabashi, Chiba.

Changing at Kisarazu.

Admiring JS2SB from the outbound train

First, take a forward-facing seat in a compartment on the right-hand side in the direction of travel.

After leaving Onuki Station and passing the second-hand-shop sign, you should be able to see it when the ironworks crane comes into view.

Shoot bursts toward the very front of your field of view, with manual focus set to infinity.

It is in the red box. Tokyo Bay Kannon is at the far right.

There.

Arriving at Sanukimachi.

The train was late, and I just missed the bus. Sometimes they used to wait…

Calling a taxi.

To Jinyaji Temple, Mount Kanozan (¥4,300, orz).

It has been mounted!!

Now, behold the majestic Yagi on Mount Kanozan!

…Oh, wrong photograph.

This one ↓.

Well…

• The photo higher up: amateur.

• The photo lower down: professional.

That is the distinction.

Enjoy the view

Click photographs in this section to enlarge.

The whole tower

From the north.

There is room to stand farther back on the south side.

Antenna

From the north. Quite a lot of sag.

From the southwest.

From the south. You can see how it is mounted.

Mounting

The whole arrangement. An impressive quantity of guy wires.

Front.

Centre.

Rear.

Station building

The HF equipment should be housed in the small hut on the right.

Beam direction

West-southwest, magnetic bearing. Aimed at 9V [Singapore], perhaps?

Getting a side view

Changing location.

A photograph looking back while moving away.

It should be easily visible from Jinyaji Temple too.

Regarding RF exposure, relative to the houses:

• There is a downward angle to them;

• The beam points somewhere entirely different.

So perhaps there is no problem?

Arrived beside NTT (click to enlarge).

On the map, I am looking in the arrow's direction.

It stands by itself in this sort of place.

Incidentally, if you look up to the left here, there is another Yagi.

To Mother Farm

Rather than stand around for over an hour* with nothing to do in temperatures of −3 to −5°C, I will get some exercise and go to Mother Farm†.

*: It is now 11:30; the next bus is at 12:40.

†: At the left edge of the map above.

Let's check whether this Yagi can be seen from Mother Farm.

A military march! Marching through the snow! ‘Across the galaxy, the horizon, and the waves’ ♪

Arrived after a 35-minute walk. Looked back. No luck—because of the weather.

It should be easily visible in clear weather.

JOSADA's tower is at the far right of the photograph.

If you visit Mother Farm, have a look, together with the next section's sites.

Speaking of Mother Farm

It is one of the relay points on the microwave routes connecting the Chikura cable landing station to Toyosu's data centres, with lower latency than fibre.

From here, long-haul space-diversity links cross Tokyo Bay.

JOSADA TELECOM makes its shot from the tower discussed in this article, farther east on Mount Kanozan.

Glad to see everyone is doing well (click to enlarge).

●HBC: High Bar Communications

https://www.tele.soumu.go.jp/musen/SearchServlet?pageID=4&IT=A&DFCD=0004121752&DD=1&styleNumber=21

https://www.google.com/maps/@35.2478688,139.936534,52m/data=!3m1!1e3

●GTT: GT Technologies

https://www.tele.soumu.go.jp/musen/SearchServlet?pageID=4&IT=A&DFCD=0003997875&DD=1&styleNumber=21

https://www.google.com/maps/@35.2464086,139.9359735,52m/data=!3m1!1e3

●NuVo Networks

https://www.tele.soumu.go.jp/musen/SearchServlet?pageID=4&IT=A&DFCD=0004176361&DD=1&styleNumber=21

https://www.google.com/maps/@35.2459382,139.9335434,52m/data=!3m1!1e3

Triumphant return to Sanukimachi Station

Mother Farm 12:45 → Sanukimachi Station 13:08.

Admiring JS2SB from the return bus

It is visible from the Sanukimachi side too. Sit on the right of the bus. After passing the nursery school, watch ahead. Red box.

There.

If you come to look, take in both stations together.

JS2SB is about a 35-minute walk from Sanukimachi Station.

Looking toward Mount Kanozan from Sanukimachi Station's footbridge

Can we see it? Mount Kanozan is around the red box.

The single tower standing apart to the right of the cluster is JOSADA TELECOM's.

The Yagi is mounted! Distance: 8 km.

Back to Tokyo

Sanukimachi 13:29 → Kimitsu 13:48 / 13:50 → Shimbashi 15:36 → Tamachi.

Sanukimachi.

Kimitsu.

Shimbashi.

Haneda new-line construction. You can get a good view down from the monorail, left in the photo.

Home around 16:00.

Expenses

¥1,694: JR, Tamachi → Sanukimachi (a paper ticket would be ¥4 cheaper).

¥4,300: taxi, Sanukimachi Station → Jinyaji Temple.

¥490: bus, Mother Farm → Sanukimachi Station.

¥1,694: JR, Sanukimachi → Tamachi.

――――――――――――――――

¥8,178 total.

Comparing Yagi antennas

Some experimental stations for HF digital fixed services use Yagis rather than log-periodics.

Click the photographs to enlarge.

JOSADA TELECOM

This site's antenna, shown again.

JS2SA 4HF

The same model: SteppIR HFT540C.

As a microwave route, this tower faces the tower in the photograph above.

JS2RB DATACOM SERVICES

The Yagi added to the existing log-periodic installation.

Because the log-periodic scatters spurious emissions?

Three directors, toward the front of the photograph, and one reflector.

Long John CL 15? Identification assistance requested.

Comparing elevations

JOSADA TELECOM is the highest-elevation site.

I have received a report that JB2XI was broken for a while ↓.

I told you so:

Comment from the person in charge of LRAJ on this situation:

How unsightly.

Updated overview diagram

Click to enlarge.

Earlier posts

‘JS2RA / JS2RB’

https://jj1wtl.seesaa.net/article/499204144.html (English translation)

‘JS2RA / JS2RB, continued’ (additional Philippines-bound Yagi)

https://jj1wtl.seesaa.net/article/505776879.html (English translation)

‘JA/CB-004’ (4HF's JS2SA and HBC's JB2XH, later classified as a receive station)

https://jj1wtl.seesaa.net/article/499505940.html (English translation)

‘JS2SA / JB2XH’

https://jj1wtl.seesaa.net/article/500304565.html (English translation)

‘The new JB2XH’ (transmit station)

https://jj1wtl.seesaa.net/article/504743515.html (English translation)

‘JS2SB’ (licence information)

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

‘JS2SB, continued’ (site photographs)

https://jj1wtl.seesaa.net/article/505597775.html (English translation)

‘JS2SB, continued again’ (building application)

https://jj1wtl.seesaa.net/article/511302814.html (English translation)

‘The Minamihara log-periodic’ (NuVo Networks)

https://jj1wtl.seesaa.net/article/501355072.html (English translation)

‘The log-periodic at Cosmo Classic Club’ (GTT)

https://jj1wtl.seesaa.net/article/508688232.html (English translation)

‘The loop array at Maeda, Minamiboso City’ (Ermis, reception)

https://jj1wtl.seesaa.net/article/515801449.html (English translation)

『JB2XI』

https://jj1wtl.seesaa.net/article/505733007.html (English translation)

‘The log-periodics at Shimoizumi, Sodegaura City’ (Ermis, transmission)

https://jj1wtl.seesaa.net/article/516751748.html (English translation)

‘The Shimoizumi log-periodics, continued’ (licensed)

https://jj1wtl.seesaa.net/article/519392776.html (English translation)

‘Microwave routes — Wakasu’ (DATACOM SERVICES and Ermis connections to the data centre)

https://jj1wtl.seesaa.net/article/517567284.html (English translation)

‘The Beverage antennas at Nuda, Kimitsu City’ (JOSADA TELECOM, reception)

https://jj1wtl.seesaa.net/article/518223542.html (English translation)

‘The Yagi on Mount Kanozan, AVANT 1’ (JOSADA TELECOM, transmission, up to just before mounting)

https://jj1wtl.seesaa.net/article/519469435.html (English translation)