EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: Alexei.Polkhanov on May 06, 2015, 05:56:49 pm
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Hi everybody, I hope there are some people on thins forum who can help me to resolve a mystery. I noticed, almost by accident, that periodically there is a lot of activity around 3.043 in area where I live - it is 26 floor (hight above ground) in downtown, Vancouver. It happens in periods and signal looks like a bunch of spikes from radar (weather radar?), but when I looked at databases and other sites like http://www.spectrumwiki.com/ (http://www.spectrumwiki.com/) there is nothing that falls into the range from 3.001 to 3.099 GHz where I see the signals - centered around 3.043GHz. There are few things that I may expect to show up above 3.1GHz and right below 3.0 but no references to band from 3.0 to 3.1GHz. Who actually is using it? Is this a natural phenomena? radar? something else?
I found this:
NEXRAD Weather Radar In the United States, NEXt-generation weather RADars (NEXRAD) operate in the band 2700-3000 MHz.
and this:
SPY-1 Shipborne Air Surveillance Radar. Tuning range: 3100-3500 MHz
but nothing in between
Someone told me that emergency services "see through the wall" scanners could be using it. Hmmmm, which models?
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Googling 3.043GHz shows some candidates like processors, T&M equipment and such.
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FCC freq allocation chart says marine navigation and radiolocation. I see a lot of licenses for the same too. And I also found a license to furuno, which lead me to this http://www.furunousa.com/ProductDocuments/FR2135S%20Brochure.pdf (http://www.furunousa.com/ProductDocuments/FR2135S%20Brochure.pdf) 3.050 GHz +- 30 MHz, 30 / 60 kw.
What kind of gear do you have? Could you put a spec-an in zero-span and get the pulse repetition and length?
Might try Canada's equivalent of the FCC to see who's licensed around you.
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OH! Canada...
Your spectral chart is here:
https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/CTFA2014EditionEN.pdf/ (https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/CTFA2014EditionEN.pdf/)$file/CTFA2014EditionEN.pdf
Steve
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FCC freq allocation chart says marine navigation and radiolocation. I see a lot of licenses for the same too. And I also found a license to furuno, which lead me to this http://www.furunousa.com/ProductDocuments/FR2135S%20Brochure.pdf (http://www.furunousa.com/ProductDocuments/FR2135S%20Brochure.pdf) 3.050 GHz +- 30 MHz, 30 / 60 kw.
What kind of gear do you have? Could you put a spec-an in zero-span and get the pulse repetition and length?
Might try Canada's equivalent of the FCC to see who's licensed around you.
Yes Canadian FCC equivalent is called Industry of Canada or something like that. They have just generic 2 900 - 3 100 - "RADIOLOCATION" and "RADIONAVIGATION".
The link to the radar info actually looks like a hit - thanks a lot! I was looking for something more specific like that. I can see a bay filled with boats and ships of all sizes from my window, but I never "heard" anything but few AIS signals.
I was using small PCB log-periodic antenna, also small vivaldi antenna (2-11GHz or so) and R&S FSL6 Spectrum analyser. I was looking for WiMAX signals but entered 3.05 instead of 3.5GHz, I realized my mistake but then I just got curious. It looks almost impossible to zero-span on it I think because spikes are appearing plus minus 50MHz at random. This is why I guessed that it is a radar.
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Zero span worked :) I think the max hold trace has only 2 overlapping passes. First pass shows signal that is stronger. It showed up again for 2-3 min and then just disappeared.
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Actually its assigned to "RadioNavigation(OR)" which is Aviation Radio Nav, Aviation Telemetry, or Radar.
Steve
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She is back. I think I know which boat it is :) They just party there as far as I can see, spinning their radar cuz it has cool looking LEDs on it.
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Interesting captures, if thats the rotation period you caught there, whatever radar that is, is spinning pretty quick!
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I am guessing you are having a lot of fun , I remember one time i was playing with a transmitter that uses 433 Mhz ( as i recall). Suddenly my brother opens my door shouting at me, asking me "what are you doing?" my car key is not working. I was laughing so hard yet excited that i was jamming the signal for him. ( the funny part for me was him assuming i was the problem)
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Anything in that area is either Dept of Defence of ESSO Australia, who use 3.05Ghz.
http://web.acma.gov.au/pls/radcom/assignment_range.range_lookup (http://web.acma.gov.au/pls/radcom/assignment_range.range_lookup)
https://www.dropbox.com/s/osqtenin83440q2/2015-05-15%2020_08_17-Australian%20Communications%20and%20Media%20Authority_%20Register%20of%20Radiocommunication%20Li.png?dl=0 (https://www.dropbox.com/s/osqtenin83440q2/2015-05-15%2020_08_17-Australian%20Communications%20and%20Media%20Authority_%20Register%20of%20Radiocommunication%20Li.png?dl=0)
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Anything in that area is either Dept of Defence of ESSO Australia, who use 3.05Ghz.
http://web.acma.gov.au/pls/radcom/assignment_range.range_lookup (http://web.acma.gov.au/pls/radcom/assignment_range.range_lookup)
https://www.dropbox.com/s/osqtenin83440q2/2015-05-15%2020_08_17-Australian%20Communications%20and%20Media%20Authority_%20Register%20of%20Radiocommunication%20Li.png?dl=0 (https://www.dropbox.com/s/osqtenin83440q2/2015-05-15%2020_08_17-Australian%20Communications%20and%20Media%20Authority_%20Register%20of%20Radiocommunication%20Li.png?dl=0)
Except he's not even near Australia.
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Anything in that area is either Dept of Defence of ESSO Australia, who use 3.05Ghz.
http://web.acma.gov.au/pls/radcom/assignment_range.range_lookup (http://web.acma.gov.au/pls/radcom/assignment_range.range_lookup)
https://www.dropbox.com/s/osqtenin83440q2/2015-05-15%2020_08_17-Australian%20Communications%20and%20Media%20Authority_%20Register%20of%20Radiocommunication%20Li.png?dl=0 (https://www.dropbox.com/s/osqtenin83440q2/2015-05-15%2020_08_17-Australian%20Communications%20and%20Media%20Authority_%20Register%20of%20Radiocommunication%20Li.png?dl=0)
Except he's not even near Australia.
Same planet anyway.
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Oh sorry, didn't realise.
As you were :)
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Keep in mind the Earth is divided into three regions for spectrum by international treaty:
Each region gets a different spectrum assignment, and each nation somewhat tweeks the International Agreement to its own uses. It gets fun when you have small countries next to each other who have to share allocations.
Some things such as Aviation, Marine Radio and Radar , Defense, and Amateur radio share some standards world wide.
For example, by treaty, North of Line "A" which is within ~70 miles of the US-Canadian Border, I loose 420-432 Mhz from my Ham Radio Privileges. Canada uses that spectrum for business and local government land mobile radio. Drive from my home 20 miles, and I can use it. There is a buffer zone along the border
Another example: In the US we have no Longwave broadcast radio, ie below 500 Khz.. Whereas Europe does.
Here is an older map of the three International Telecommunications Regions. Each one has a massively different spectrum, allocation above 30 Mhz.
http://www.itu.int/ITU-R/information/docs/emergency-regions.jpg (http://www.itu.int/ITU-R/information/docs/emergency-regions.jpg)
It looks like 2900 to 3100 is an older marine radar allocation.
Steve