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Picking up HAM or CB talk over PC speakers

By circusboy01
Jan 1, 2011
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  1. I just didn't know where else to post this question.

    I'm hearing H.A.M. operators,or people using C.B. radios ( not sure which) over my PC speakers. It's not real loud.I have to put a speaker up to my ear to hear what their saying,and turning the volume up or down has no effect. But. It's like a mosquito
    buzzing in my ear.It's very irritating,and I just want it to go away. Please,somebody tell me how to make it go away. Maybe you know of a filter I can buy or something.
    Thanks in advance. CB.


    EDIT; A few hours later.
    I was wrong about the volume control having no effect. I had my remote device ( part of my speaker system) turned way down..
    Problems still the same though. In fact their yaking up a storm right now. Wouldn't be so bad if they had something worth saying LOL
     
  2. Benny26

    Benny26 TechSpot Paladin Posts: 1,577   +47

    I've had this with my TV in the past. It stopped after a few days, so it wasn't major. Anyways, the only stuff i know that can stop radio interference, is a type of wire mesh (sometimes like silk)

    Apart from that, i'm not too sure.
     
  3. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12

    Thanks Benny. If thats the answer,maybe someone will elaborate on it for me.
    Like you Iv'e had the problem on my TV in the past,and it comes back every so often.I figure maybe it's a trucker who stops off in town every once in a while,and spends hours on his CB. It's always the same voice.Hopefully if I can fix it on my PC I can fix it on my TV.

    I could have sworn I posted this in milestones. Don't know how it got here in Hardware
    CB
     
  4. mike1959

    mike1959 TS Addict Posts: 1,122   +22

    You need to get 2 ferrite chokes to clip onto the speaker wires, right at the back of the speakers. These hinge open, you wind the speaker wire around one half, about 2 or 3 times, then snap the choke shut. These are known as 'interference suppressors', and the job they do is to block high frequency Radio signals (27MHz),
    but let audio signals through. You hear radio signals because the long leads of your speakers are an antenna, the amplifier in the speakers makes it loud enough for you to hear. You can wind the extra wire to your speakers into a small bunch, and wrap tape around to make it less like an antenna, but the suppressors are the answer. If you have an old a.m. radio you don't want anymore, take out the ferrite rod antenna, you will see it has many hundreds of turns of wire on it, take all the wire off, then wind your speaker wires around it, say 10 times, and hold it on with tie-wraps, or tape.
     
  5. Benny26

    Benny26 TechSpot Paladin Posts: 1,577   +47

    :D Yeah, the moderators move things about alot.
     
  6. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12



    Kinda thought thats what happened. You'd think they could leave a message,like Your post has been moved to...
     
  7. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12

    Thanks Mike. Should I try to get them online or do you think maybe Radio Shack or Best Buy might be better? Same kind for PC and for TV right?
    Thanks again Almost forgot.. Do these things have teeth on them,and do i need to squeeze them hard enough to penetrate the wires coating CB
     
  8. mike1959

    mike1959 TS Addict Posts: 1,122   +22

    The idea of these 'chokes' is that you pass the speaker wire through the middle, then once or several times over the outside, back through the middle, then snap the plastic case shut. The 'choke' is made of 'ferrite' material, basically iron, and is formed in the shape of a tube, about 25mm long and 15mm wide. But it is made in 2 halves, with a hinge so that you can get it over the wire, without cutting the wire.
    You don't break into the wire at all, it works because the radio signals flowing along the wire see the ferrite as a high resistance, but the audio signals get through.
    You can clip these over the mains lead, and/ or speaker leads, try both ways.
    Some computer speakers are fitted with these from new, eg. Altec Lancing XT1.
    I found a picture of one here; http://www.radioshack.com/product/index.jsp?productId=2103222
    The reason I said about the A.M. radio, is that the 'Loopstick' aerial inside, normally 50mm x15mm, is made of the same material, and by winding the speaker wire around it, say 10 times, it will have the same effect, and will be free if you were going to scrap the radio anyway!
    Also have a look at this page, but don't know if they will sell you 2, maybe 2000! http://www.leadertechinc.com/bisectedround.shtml Notice how they clip over the cable without breaking into it.
     
  9. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12

    Thanks again Mike.Your link showed a thing called a 100 pH RF Choke for $1.49
    Skinny thing with what looks like two long wires coming out of both ends.
    Would that work? Because I need Four of them 2-TV 2-PC and I sure like the price I f I can use that one I guessing you hold it parallel with the speaker wire wrap the speaker around a few time then take the wires sticking out of the thing and wrap them around the wire bundle .
    Am I anywhere near correct? I am using Altec Lancing XA3021 speakers on my computer but their about 6 years old
    O.K. Gonna go Ferrite choke pricing. In case that 100pH thing wont work for my problem CB
     
  10. jobeard

    jobeard TS Ambassador Posts: 13,476   +329

    I've done Shortwave radio in the past so maybe I can help.

    First choice is to use shielded wire; outside connection is braided shielding which connects to the ground connection on the connector. the inside wire is stranded wire and connectes to the center probe of the connector.

    Second choice is called a low-pass filter
    :
    that inductor goes in series with the center wire on the shielded cable.
    then you take a 0.001 uuF capacitor and wire it between the shield and the center wire.​
    You can get the shielded wire, inductor and capacitor from Radio Shack

    Place this low-pass filter at the speaker end of the wire.

    btw: if you have microphone input and it's connected to the PC, use the same setup but
    place it nearest the PC connection.
     
  11. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12

    Are you saying mikes way wont work,and it has to be done the way you explain it in your post? Or,are you just showing me another way? Thanks CB
     
     
  12. jobeard

    jobeard TS Ambassador Posts: 13,476   +329

    the low-pass filter is more effective. the ferrite cores work for very high frequencies
    but is very frequency dependent. The low pass filter gets more agressive (does better) as the frequency increases,
    and will cut off everything above 30,000 cps (or 30khz)
    (which is ~ 2x the audio limit and below the Loran range).

    Citizen ban is 27mhz (~9 meter ban)
    20 meters is where Domestic TV was located 54mhz
    40 meters is ~ 120mhz (local air traffic ban)

    and our cordless phones, cell phones and wifi-Gmode stuff is way beyond at 2.4ghz

    either way, the stuff is cheap either way and it's easy to try either or both :wave:
     
  13. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12




    Thank you jobeard Maybe I will try both. one on my TV the other on my PC
     
  14. jobeard

    jobeard TS Ambassador Posts: 13,476   +329

    Can't tell where you are located (hint: add city,country to your profile)
    nor if you're in a rual or urban setting, but - -

    If you drive around the neighborhood and see a tower,

    [​IMG][​IMG][​IMG]

    that person is a shortwave enthusiast. Here domestically (U.S.), he is required by the FCC to avoid R.F. interference and/or to help you shield your equipment from his side-effects.

    It's easier to catch flies with sugar than vinegar, so be nice when you approach him/her on the subject.
    Explain the situation and ask if he would be so kind as to help you.
    Report the low-pass filter idea and ask the specific pH + uuF values that you should use.
    It should not take much time and he should be glad to help you out.
     
  15. mike1959

    mike1959 TS Addict Posts: 1,122   +22

    RF Choke

    Here are some photos of what I have on my speaker leads, you will see the thin speaker lead goes through twice. They are made to clip over a mains lead as well,
    and are designed to block any radio signals from getting to your speakers.
    They can be used on anything from tv, radio, Hi Fi or computer.
    You can see you don't cut into the wire at all, no need. The dark material inside is the ferrite choke, with the plastic case just to hold it together.
     

    Attached Files:

  16. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12

    Hey Mike; you know what they say about a picture being worth a thousand words.
    Your post proves that point.I wasn't 100% sure of how to wrap the wire. Now I am Thanks.
    Questions. My speaker wire is a lot thinner than what you show in your pictures do I need to wrap it a few more times? Never mind.just looked at your post again. You wrap them around twice.
    The speakers on my PC plug in separately to the sub-Woofer,so I know I will need 2 of the chokes.
    What about the speakers I'm using on my TV? One speaker is the power speaker,
    everything plugs into it. Including the other speaker. The speaker wire is attached to it and plugs into the power speaker.
    Would I need one just a little ways back from where the speaker wire plugs into the power speaker,and one just a ways back from where the wire comes out of the other speaker? Or. JUst one for the power speaker?
    Sorry I took so long to respond. I was over at Windows OS working on another problem.Waiting for you to tell me how many chokes I need ,so I can know how many to order on line. Thanks again. CB
     
  17. mike1959

    mike1959 TS Addict Posts: 1,122   +22

    RF chokes

    Hi, this type of choke is made to fit over the mains AC lead, but you can see in my photos, that Altec lansing have used them to wind the thinner speaker wire through.
    The CB radio signals you hear in your speakers are being picked up in all the wiring in the house, you can't stop that, but you can stop it getting into the TV, PC or radios, at the point where the mains leads plug into the wall. So on a TV you would put a choke on the mains lead right near the back of the TV. If you have a separate sound amp, eg, 2.1 surround, for TV, then you put a choke on the mains AC lead of that. In other words, you have to block the interference BEFORE it gets amplified. You can put chokes on the speaker leads as well, if the breakthrough is very bad but I don't think you will need to. You can wind thinner wire through as many times as will fit, and it will reduce the breakthrough with more turns. So for how many you should order? In my opinion it's one for each mains lead you have problems with. If you power your TV or PC from a 4 or 6 outlet gang plug, you only need one choke to go on the mains AC lead into the wall outlet. If you still have RF breakthrough after that, then one choke right at the back of each speaker, (as I have in the photos). Hope that helps !! (Can't give you any part numbers to order, because our parts suppliers won't mean anything to you in the USA,, eg Farnell, Electrovalue, Maplin, but they are available worldwide.) But this is a start, maybe more info than you wanted !! http://www.mouser.com/catalog/637/919.pdf
     
  18. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12

    O.K. I think I got it. Put the chock on the cord from the surge protector to the wall.
    Problem: chord from surge protector is pretty thick.don't know if I can do the wrap around without kinking it. Can I put the choke on with out the wrap around ? Or.Better yet. Can I put the choke on the cord coming from the speakers AC adapter to the surge protector. The chord is smaller,so the wrap around would be easy, And it's well before it gets amplified. CB
     
  19. captaincranky

    captaincranky TechSpot Addict Posts: 10,987   +957

    Going back to prior suggestions, if this is CB interference, you'll likely be able to do nothing about it, since CB is completely license free. However, if it is ham radio, try and determine the operator's call sign, you may be able to track them through that.

    However, the FCC can't keep up with all the clowns that summarily, (and quite illegally), decide to put power amps on their CB radios.

    That said, have you verified the ground integrity of your house wiring?
     
  20. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12


    Are you saying that the chokes that Mike 1959 suggested wont work if it's CB interference?
    Guess I'll look around the neighborhood for Ham operator antennas ,or maybe a big rig parked in front of somebody's house.
    Just thought. I'll bet it is a Ham operator, Because I never hear him say anything like breaker breaker, or 10-4 good buddy. Like you hear truckers say on TV and movies.:) Don't have a clue how to test ground integrity on this mobile homes wiring. Thanks for posting CB
     
  21. jobeard

    jobeard TS Ambassador Posts: 13,476   +329

    Not entirely; they still have to apply and be accountable (and that's really your well taken point) for the issue to be issued the call-sign.
    Better to fit over the mic and speaker leads. The power supply has large capacitors and they
    will filter all that stuff. *Maybe* the choke would help on a laptop with the A/C adaptor however :)
     
  22. captaincranky

    captaincranky TechSpot Addict Posts: 10,987   +957

    Not exactly. What I meant was this; CB is limited to 5 watts, at the final amplifier, but many people put illegal high power amps on their CB rigs. Since the operation is license free, and so many people are doing it, the FCC can't catch them all.

    Ham radio, on the other hand, IS licensed. But, the transmitters are allowed to be much higher power, on the order of a 1000 watts. I was suggesting that you could obtain a ham radio operator's address through his, (or her), call sign from the FCC under FOIA. Ham operators are much more likely to cooperate with, and assist you in, resolving this issue. Illegal CB operators, well, not so much.

    I made no comment on the efficacy of the inline chokes. It's something you SHOULD try. If that particular product won't fit your AC lines, then google TVRI filters, there are, I"m sure a lot of products out there, that might be more suited to your installation.

    "Ground integrity", can be checked with a simple AC neon tester. This is done by placing the tester's leads from the hot wire, (narrow blade) of the socket, to the ground pin, (big round pin). If the tester lights, the ground is good. http://www.google.com/imgres?imgurl...3bDQ&esq=1&page=1&ndsp=51&ved=1t:429,r:17,s:0 Incidentally, that's the longest URL I've ever seen!

    Also, Cooler Master supplies TVRI suppressors with its cases. These are little magnetic "thingys", shaped like, and close to the size of, a "Lifesavers" candy. You're supposed to pull the front case wiring through them. (methinks).

    @ Jobeard; yes, I realize that a CB permit must be obtained. I also realize that to obtain a Ham radio license, you must be tested, and be very knowledgeable in the field. (Do they still require Morse code @XXX WPM)? In short, this is a better class of operator, who would most probably be more sympathetic.
     
  23. mike1959

    mike1959 TS Addict Posts: 1,122   +22

    RF chokes

    I have taken two more pictures of my RF choke set-up. They make chokes to fit all sizes of wire, they will definitely make some to suit your wiring no matter what you have. On mains wiring, ( 13 Amp, 3 core ) the overall with is probably 8mm, and one of my photos shows that. The other photo shows it on my PC 4 gang outlet.
    It only passes through once on a mains cord. If you are using a thicker cord, then order the slightly wider choke to suit. Note that you don't need to cut the wire in any way, they are designed to fit over the outside and the case clips together to stop it moving along the cord. The idea is that you fit the choke to block the radio signals getting into your amplifiers, (e.g. surround sound, TV, PC, Hi-Fi.) Only if the unwanted signals are still there, you can put extra chokes just behind the speakers.
    Just noticed that my monitor leads have them fitted too. Have done a search on 'Digikey' website, and they do stock the type I use. It will take up to 9mm mains cord. Part 445-2046-ND http://search.digikey.com/scripts/D...ang=en&site=us&keywords=445-2046-ND&x=31&y=22
     

    Attached Files:

  24. jobeard

    jobeard TS Ambassador Posts: 13,476   +329

    :wave: correct
     
  25. circusboy01

    circusboy01 TS Enthusiast Topic Starter Posts: 884   +12

    Mike and Jobeard Those pictures look like the size cord coming from the wall to myMulti-outlet surge protector.I'll measure it tomorrow. I understand about not cutting the cord.Ok I have to block it before it gets to the amplifier. which means I have two choices. On the thicker cord that plugs the surge protector to the wall socket.Or on the smaller cord that plugs the amplifier to the surge protector..Right?
    Both are before the amplifier.Maybe I'll put one on both cords.( before and after the surge protector.Unless any of you think that might be a waste of money
    . I'll get those chokes on real soon. So I can let you guys go on to help somebody else
    I feel like I'm taking to much of your time. It's like each answer I get. Brings to mind another question. Again. Thanks to all for the help.
     


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