Results 1 to 8 of 8

Thread: RF question

  1. #1
    Join Date
    Sep 2006
    Location
    Netherlands
    Posts
    1,435

    Question RF question



    Is there anyone who could identify a possible source of this 460MHz broadband burst ~5sec on / ~16 sec off, that is swamping my 434MHz ecg telemetry devices ?

    Does anyone recognize this kind of RF behavior ?

  2. #2
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Tetra? Its not that spread, and its strong. Might be radiolocation bursts.

    Duration makes it look like digital voice, or LONG data bursts, maybe radiolcation.

    434 Mhz, the international, license free, low power car key fob frequency for a ECG? Wierd choice of allocation for a medical device.

    I could understand the 406 Mhz medical telemetry band, but 434?

    434 Mhz is SMACK in the middle of a international amateur (HAM) radio band.

    432 in the US is a secondary to Amateurs and Primary allocation to big Military Radars.
    Its that way in much of the world. Of course my countries military tends to radiate whatever they want where ever they are.
    As do many others.

    430 to 440 is usually Ham, Although in the US and many other countries 440 to 450 is also Ham.

    I need a frequency allocation chart for the Netherlands/Region . That is a pretty broadband burst.
    I can help you if I see a allocation chart in English.

    OK, found the Netherlands allocation search but not the overlapping Europe International band chart. Here it is:

    Here is your version of our Federal Communications Commission.

    http://loket.agentschaptelecom.nl/nf.../freqPortal.do

    Here is the frequency allocation search engine:

    http://www.agentschaptelecom.nl/onde...uentieregister

    http://loket.agentschaptelecom.nl/nfr

    Click on the colors of the chart generated and it tells you in more detail what each is. Search 10 Mhz either side of your frequency.

    Since your in Europe with its mish-mash of regulatory agencies and allocations, you may find its a device from out of your borders.

    Under Euro rules Football, your device is possibly a SRD

    http://en.wikipedia.org/wiki/Short_range_device (MEANS YOU THE USER NEED TO "EAT" THE INTERFERENCE)

    My bet is the Agentschaptelecom can either look in the license data base by location, or actually RDF (HUNT) the offending widget

    Hunting tools: Antennas: http://www.qsl.net/w4sat/antlegn.htm and http://www.wa5vjb.com/products1.html and http://www.qsl.net/ve3rgw/corner.html

    440 Mhz Yagi designs are all over the net.

    You can make a crude corner reflector with a piece of sheet metal.

    Steve (Wearing his "Spectrum Management" hat)
    Last edited by mixedgas; 10-23-2012 at 08:21.

  3. #3
    Join Date
    Jun 2009
    Location
    The Woods, CA, USA
    Posts
    534

    Default

    RF Explorer is great bang for the buck for hunting down stuff. Can also use as an RF generator http://micro.arocholl.com/

  4. #4
    Join Date
    Sep 2006
    Location
    Netherlands
    Posts
    1,435

    Default

    Found it !
    Thanks everybody.

    It ended up being a defect in a relay transmitter for the personal paging system @ 466.450Mhz.
    When working properly, it should take some kHz bandwidth, NOT ~100 Mhz !

  5. #5
    Join Date
    Apr 2012
    Location
    Beaverton, OR
    Posts
    292

    Default

    Another thing to look at in the future is that some smart utility meters work in the 450mhz band. These could be power, water, or natural gas.

  6. #6
    Join Date
    Apr 2006
    Location
    Miami, FL
    Posts
    3,590

    Default

    never seen any in UHF (450~Mhz) those are all licenced frequencies over here, mostly public safety, then shared 2 way etc... the entire 470-512mhz (aka T-Band) is going away over here soon too, rumor has it its going to cellular...

    actually most of the smart utility meters I have seen are in the 902-928mhz ISM band (ham is higher than ISM in that band, love keying up my 250w 900Mhz PA's all over those smart meters lol)

  7. #7
    Join Date
    Dec 2008
    Location
    Vezon, Belgium
    Posts
    1,017

    Default

    could also be some ethernet powerline communication adapters in some cases, the new hi-speed ones could be in that range

  8. #8
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Quote Originally Posted by flecom View Post
    never seen any in UHF (450~Mhz) those are all licenced frequencies over here, mostly public safety, then shared 2 way etc... the entire 470-512mhz (aka T-Band) is going away over here soon too, rumor has it its going to cellular...

    actually most of the smart utility meters I have seen are in the 902-928mhz ISM band (ham is higher than ISM in that band, love keying up my 250w 900Mhz PA's all over those smart meters lol)
    Flecom, is any one going to enforce Refarming/Narrowbanding? I smell a fee sharing possibility for contractors with the FCC. I'm already seeing piles of "wide" radios hitting the surplus market... God knows the friendly candy company killed its own enforcement staff off in the Clinton years. So who is going to go say your too Wide, here is your fine?

    Change that to fiendish costly candy, spectrum use was never ment to be auctioned or taxed... &^%$ lawyers.....

    I hate the Idea of needing 2-4x more narrow radios to cover the city. Of course my stuff is Ham, GMRS, and MURS, so I miss the whole mess.

    They can have T-band. I'm too close to Canada to use it. Ie I'm North of "LINE A" in the UHF regulations. Just leave 2 meters and 44o and 10 Ghz alone and I'll be happy.

    Steve

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •