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Which Filter Should I Use....

Discussion in 'General CB Services Discussion' started by Eastside, May 13, 2011.

  1. Eastside

    Eastside Well-Known Member

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    to keep my CB out of neighbors LL?


     

  2. Beetle

    Beetle Sr. Member

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    I've heard a few good things about these: Modem filters - modem filters online - affordable telephone rfi filters

    (And here I'm assuming that LL = Land Line = telephone). The telephone should have a Part 15 label on it, indicating that it must not interfere with radios and must accept any interference from licensed radios. Since CB is an unlicensed service, however, Part 15 is out the window.
     
  3. Eastside

    Eastside Well-Known Member

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    I was looking for advise for a filter for my radio....I was told not to get involved with giving my neighbor any devices to put on their ph......I was out to the cb shop and the tech told me to put loops in my coax up where the coax connects to my imax....but I really do not want to do that yet...because I plan on getting rid of the imax and getting a aluminum base antenna.

    My neighbor is not upset...he said it only bothered an old wall ph they had in the kitchen....that it did not bother the tv or any of the cordless phones.....I can key down my cobra 148 with my cordless ph here on my desk and it does not make any interference at all....does not make any interference with any of our phones....but I want a filter just to make sure that I am not bothering anyone.
    My antenna and radio are grounded.
     
  4. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    There is no filter made in the world that will do what you want. Since the problem is not harmonics then a low pass filter on the radio will not do any good. Since the problem is with a phone connected to wires the problem will noit be cured with the use of a high pass filter which is usually used on a TV set. The problem is RF pick up by the device being interfered with and as such the ONLY place the problem can be cured is at that device. There is nothing that can be done for filtering on your part. Beetle had the answer, an RFI filter on the phone line.
     
  5. HiDef

    HiDef Active Member

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    Take the advice and put a coil BalUn at the stick. That will keep your coax from acting like some of the antenna.

    Those who tell you no filter on your end will stop your specific problem are correct.
     
  6. Eastside

    Eastside Well-Known Member

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    Thanks for the info fellas......glad I did not purchase one of those low pass filters if you say they won't work. :)

    And I will get up on the roof whenever it quits raining and loop the coax.
     
  7. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Like HiDef says, the loop may prevent feedline radiation and IF that is the problem then it MAY solve the issue. If not then the only answer is a filter on the neighbor's phone line. Solving RFI issues is :censored: :headbang :bdh: at best most of the time. Been there, done that, almost wrote the book on it. :laugh:
     
  8. Eastside

    Eastside Well-Known Member

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    When I had my DSL installed they gave me ph filters...I wonder if they would work?
     
  9. dudmuck

    dudmuck Active Member

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    That could be your problem.
    What hidef said, the balun.

    Perhaps your antenna doesnt have a good ground plane (the 2nd half of antenna).
    Could be its trying to use whatever metal antenna is mounted to, and is wasting RF energy where you dont want it.
     
  10. Eastside

    Eastside Well-Known Member

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    I don't know if this means anything....but I have a flat match.
     
  11. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    It's worth a try. They are a low pass filter meant to keep the higher frequency data signals from being heard. I did use a DSL filter to get rid of some trash I was picking up on a telephone line being used for a backhaul to the radio station and it worked fairly well.
     
  12. the imax doesn't have a ground plane unless you add one to it . but you could consider the coax shield or the mast a ground element . but that's known to cause bleeding problems .
     
  13. hookedon6

    hookedon6 W9WDX Amateur Radio Club Member

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    well, there's your answer,............... give your neighbor your cordless and tell him to throw his old phone into the chit can;)
     
  14. Eastside

    Eastside Well-Known Member

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    Yeah.....I kinda hinted at that....but you know how it is.....they got it in their heads that its your equipment not theirs thats needs upgrading.
     
  15. hotrod

    hotrod Well-Known Member

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    does your radio have the audio limiter still intact?
    are you running a amp?
    are u running a power mic?if so keep mic gain on cb down
     

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