Chinese CODAN intruding into the 40m band

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ka3jjz

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From Ary Boender in the UDXF- the list of logs is too long to post here, but here's the test. Any transcription errors are mine...

Since mid 2016 I logged CODAN selcalls on 7, 8, 11 and 13 MHz. Until a week ago I didn't know who they are. Australian State Emergency Services was
suggested but there are too many stations and they are also transmitting 24/7. That doesn't fit the SES activities. Besides that SES and affiliated
service do not use these frequencies. So, if it isn't the SES, what is it???

It appears to be a HF Vehicle Tracking System. The syatem is used by companies in various countries, but the specific traffic that I heard all
come from one place: the Spratley Islands in the South China Sea. China is building artificial islands in the Fiery Cross Reef. The Chinese started
their activities in 2015. The first transmissions from that area were noticed in early 2016. The tracking system uses CODAN equipment that sends
selcalls to base stations. The base stations use the received data to track the ships, barges and cars used for the building activities. Sometimes GPS
data is mentioned in the CODAN messages, but so far I have no idea how to read it.

Voice traffic has been heard in Mandarin following CODAN calls. These are actual calls, not the tracking devices. They are answered by the reverted
tones sent by the receiver's CODAN radio to acknowledge the receipt of the signal.

Base stations IDs include: 1111, 2222, 3333, 4444, 5555, 6666, 7777, 8888, 1188, 6363, 6969, 7474, 7979, 9898, etc. Note the combinations: either XXXX
or XXYY or XYXY. Easy to recognize. These IDs are in the "TO" field.

Frequencies in USB. The center frequency is 1785Hz higher.

7103, 7106, 7109, 7112, 7121, 7124, 7127, 7130, 7133, 7139, 7142, 7145, 7148, 7157, 7160, 7918, 7921, 7933, 7936, 7938, 8003, 8006, 8009, 8012,
8015, 8021, 8024, 8027, 8030, 8033, 8041, 8066, 8072, 8075, 8078, 8596, 9047, 9090, 11149, 11159, 11163, 11168, 13431, 13452 kHz and maybe more. The
Chinese are intruding the 7MHz HAM bands with this service.

Examples of GPS data:
ESN 117117
ESN 117255
 

VK3RX

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Thanks for this post.

Last October we had interference on 40m from OTH-SW Chinese radar from the same region. It was reported to our WIA Intruder Watch who also file reports to the ACMA (our equivalent of the FCC), and a couple of weeks later it moved down to just below the 40m band.
 

ka3jjz

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I'm sure it's already been brought up at the ITU - unfortunately they have little if any enforcement ability, plus, as the article points out, the transmissions are coming from the artificial disputed islands on which the PRC has been building military bases. They'll never really even acknowledge this interference. And it's been going on for almost 3 years now. What a pain....Mike
 
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