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Author Topic: 3.139MHz USB Japanese chat  (Read 947 times)

Offline Looking-Glass

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3.139MHz USB Japanese chat
« on: March 17, 2018, 2110 UTC »
Came across two Japanese men chatting away for well over an hour on 3.139MHz USB this morning at 1820z onwards. Conversation went for nearly 90 minutes.

They are not in Japan as the signals were around 5X9 peaking plus 20dB over at times.  Audio quality sounded like base station operation and not fishing trawlers.  One had a 30 second "beep" tone on his transmission, like in the old days of timed radio telephone calls.

Japan conducts many aid projects in the Pacific Islands, also logging projects in the Solomon Islands and Papua New Guinea, so I tend to think they are in the South Pacific region as signals from Asia were very poor this morning.

If any one has ideas on this mystery logging, would be appreciated. :)   

PS:  This pair seem to be active every morning at the same time, checked back last two mornings and they were there chatting away.  Also heard at 1120z so suggests this is a common meeting frequency?
« Last Edit: March 26, 2018, 0813 UTC by Looking-Glass »
Hermitage Flat, NSW.

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Yaesu FT-2000D, ICOM IC-736 HF/50MHz, ICOM IC R75 & Tecsun S-2000 to 450 feet of wire, and a multi band vertical of dubious reliability.

Offline R4002

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Re: 3.139MHz USB Japanese chat
« Reply #1 on: March 31, 2018, 1714 UTC »
I do recall your excellent research regarding the missionary HF nets in your part of the world, 3139 kHz is another great catch.  Does anybody on this board speak Japanese?  Would be a nice catch if you could get a recording and a translation.

A cursory Googling comes up with very little on 3139 kHz / 3.139 MHz.  It lies in the upper portion of the 2850 kHz to 3150 kHz aeronautical band, which is often home to weird fixed/mobile and military [and unlicensed] stuff...[at least in the Americas, I'm sure in your part of the world its similar].

The Japanese table of frequency allocation lists 2850 kHz to 3025 kHz as AERONAUTICAL MOBILE (on route) and 3025 kHz to 3155 kHz as AERONAUTICAL MOBILE (off route) which doesn't help much.  3155 kHz to 3400 kHz is FIXED/MOBILE EXCEPT AERONAUTICAL MOBILE which seems to fit better with what you're describing. Considering the strong signals and 30 second timer beep, its likely not just some guys with 100 watt ham radios talking out of band. 
« Last Edit: March 31, 2018, 1715 UTC by R4002 »
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers

Offline Looking-Glass

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Re: 3.139MHz USB Japanese chat
« Reply #2 on: April 02, 2018, 0522 UTC »
R4002:  The plot thickens with these Japanese chaps chatting on the 3MHz band, found two others:

1829z  3.310MHz  USB  Two Japanese men chatting, frequent mention of figures/numbers. One is 20dB over nine with a lot of background noise, the other 5X3 at best.

1758z  3.300MHz  USB  Two Japanese men chatting for well over an hour, both around the 5X6 to 5X9 mark.

No mention of "Gyogyo" which is Japanese for Fisheries, heaps of numbers mentioned on the 3.310MHz chat, with short overs, maybe fishing catch figures or timber harvest figures?

Around the same time the drift net beacons on 2MHz were quite strong too, this again suggests the Pacific region, the Japanese shortwave station on 3.480MHz was only 5X5 report at best so these fellows are in this region somewhere.

Don't have the technology here to record the chats, I notice good manners used when handing contact over, unlike the trawlers which are abrupt and talk very quickly and you often hear the vessels background noise. 

The mystery continues... 8)
Hermitage Flat, NSW.

Grid Square:  QF56dm.

Yaesu FT-2000D, ICOM IC-736 HF/50MHz, ICOM IC R75 & Tecsun S-2000 to 450 feet of wire, and a multi band vertical of dubious reliability.

Offline Looking-Glass

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Re: 3.139MHz USB Japanese chat
« Reply #3 on: May 20, 2018, 2208 UTC »
Have established that the regular Japanese chat on 3.139MHz USB belongs to a Japanese fishing trawler company.

Between 1900-2000z this morning, my time, heard at least six or seven check ins, the exchange of figures between the base was evident.

A couple of the stronger check ins had "mechanical" background noise sounding like engines going full throttle.

Pity the Japanese fisheries data base don't list private company HF fixed base allocations, otherwise a confirmation would be more forthcoming... ;D
Hermitage Flat, NSW.

Grid Square:  QF56dm.

Yaesu FT-2000D, ICOM IC-736 HF/50MHz, ICOM IC R75 & Tecsun S-2000 to 450 feet of wire, and a multi band vertical of dubious reliability.

Offline Josh

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Re: 3.139MHz USB Japanese chat
« Reply #4 on: May 21, 2018, 1617 UTC »
Don't let signal strengths fool you. If propa is working out well for them they could be in home waters and 60 over at your location. In early ww2, the fcc rid was alerted to a strong Japanese signal from some army signal corps unit in California as saying there must be a spy on the mainland or a nearby warship for that strong of a signal, turned out to be the naval hq station in Tokyo.

The fcc rid built a listening post in Hawaii in the crater of a "extinct" volcano. Reason why is US gov officials wanted to know what the Japanese gov was telling its citizens in their home radio bcasts, so fcc rid laid out a beverage in that crater. Tokyo on mediumwave came in like a local at almost any time they wanted to tune in, that salt water from Tokyo bay to Hawaii makes for a great groundplane. They recorded the bcasts on wax cylinders and 78rpm records and then flew them on to Washington DC. And now you know!
Conveniently located near Vincennes Indiana.

Offline R4002

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Re: 3.139MHz USB Japanese chat
« Reply #5 on: May 23, 2018, 1523 UTC »
Have established that the regular Japanese chat on 3.139MHz USB belongs to a Japanese fishing trawler company.

Between 1900-2000z this morning, my time, heard at least six or seven check ins, the exchange of figures between the base was evident.

A couple of the stronger check ins had "mechanical" background noise sounding like engines going full throttle.

Pity the Japanese fisheries data base don't list private company HF fixed base allocations, otherwise a confirmation would be more forthcoming... ;D

Any similarities between your now sort of IDed activity on 3.139 MHz / 3139 kHz and the other activity heard on 3.300 MHz / 3300 kHz and 3.310 MHz / 3310 kHz?  The sound of a marine engine the background is naturally a dead giveaway :D 

Sounds like propagation to Looking-Glass's location is pretty well regardless, going by his mention of the driftnet beacons in the 2 MHz region
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers

Offline Looking-Glass

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Re: 3.139MHz USB Japanese chat
« Reply #6 on: May 25, 2018, 0652 UTC »
I arrived at the "local region" conclusion due to the fact that NHK Japan and Korean shortwave stations on 3 and 4MHz have been poor in signal yet these Japanese fellows on 3.139MHz etc are quite strong.

Will look at comparison to signal/traffic on 3.300MHz and 3.310MHz later when time permits, although 3.139MHz seems to be more busier than the others.

A surprise about a month back was three people chatting in Portugese on 4.900MHz USB around 0925z.  The 4MHz band was totally flat to Latin America at the time and yet to open fully to Europe.  The signals were quite strong with one fellow nearly 10dB over nine, the others were perfectly readable.

Portugese is spoken in their former Asian territory of Macau and East Timor (Indonesia) so my guess is maybe there, no repeat traffic heard after subsequent monitoring.  May have been Brazilian drug smugglers on a mother ship in the region too.

Never a dull day on HF eh? ;D
Hermitage Flat, NSW.

Grid Square:  QF56dm.

Yaesu FT-2000D, ICOM IC-736 HF/50MHz, ICOM IC R75 & Tecsun S-2000 to 450 feet of wire, and a multi band vertical of dubious reliability.

Offline Looking-Glass

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Re: 3.139MHz USB Japanese chat
« Reply #7 on: May 28, 2018, 0630 UTC »
Both 3.139MHz and 3.310MHz USB both appear to be Japanese fisheries, base on land or mother ship at sea (I think it's the latter) talking to vessels out at sea, lots of figures exchanged which suggests catch numbers.

3.310MHz was coming in well this morning and after 20 minutes of listening found similar format to that of regular 3.139MHz, probably a different company.

Each company probably has its own in house frequency, seems to be a few of them in the 3 and 4MHz band.  Nothing noted on 3.300MHz USB though.

Another group noted on 3.430MHz around 1800z with strong signals, Japanese, and same format as the other logged.
« Last Edit: May 30, 2018, 0644 UTC by Looking-Glass »
Hermitage Flat, NSW.

Grid Square:  QF56dm.

Yaesu FT-2000D, ICOM IC-736 HF/50MHz, ICOM IC R75 & Tecsun S-2000 to 450 feet of wire, and a multi band vertical of dubious reliability.

Offline R4002

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Re: 3.139MHz USB Japanese chat
« Reply #8 on: May 30, 2018, 1359 UTC »
I have a hunch that some of the Spanish language traffic I hear in the upper parts of 6 MHz region (and elsewhere, namely 11-12 MHz and of course 26-28 MHz) is related to smuggling...wouldn't surprise me if you're hearing some as well.  I remember watching a documentary about narco-submarines coming out of South America and meeting up with fishing vessels and they showed the interior of a captured narcosub and the communications equipment consisted of an Icom IC-M700 HF-SSB marine radio and a transponder for those driftnet radio buoy beacon systems that use selective calling.  Apparently they're dragging shipments behind these ships in bouys that are mocked up to look like driftwood and using driftnet radiobuoys to keep track of them in case they have to cut them loose when the Coast Guard comes a-knockin'.  From what I could tell, its the ones that operate in the 1.6-4 MHz region...

I also agree with your theory about a "house frequency" or "company channel" that may or may not lie outside the ITU marine bands/ITU marine band channel plan.  Find an unused aero frequency in the 2850-3150 kHz range or the 3400-3500 kHz aeronautical bands, or use the portions that are actually assigned for "fixed/mobile".  You know, because Japanese fisheries and drug smugglers are very worried about following ITU band regulations ;)
« Last Edit: May 30, 2018, 1403 UTC by R4002 »
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers