Where should ferrite chokes go?

Discussion in 'Archived Threads 2001-2004' started by Timber, Oct 22, 2002.

  1. Timber

    Timber Stunt Coordinator

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    I just got some ferrite chokes for the various cables in my system and needed some input. Now which cables should I put them on and which end of the cable? I was assuming the best place to put them is on power and video cables. Would speaker and audio cables benefit much? And does it matter which end of the cable I put it on - source or receiving end? Almost forgot, which components stand to gain the biggest improvement? I realize the improvements may be minimal at best, but I just wanted to see what you guys thought. Thanks for input.

    Tim
     
  2. Saurav

    Saurav Cinematographer

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    Usually the receiving end. The reasons for that are a little technical and I don't completelt understand them myself. I thought it was so that any RFI picked up in the cable doesn't enter the destination component, but it's not that simple [​IMG] Something to do with presenting a high impedance (at RF frequencies) in one direction and a low impedance in the other direction.
    Which cables to try it on - depends. I've heard of people saying that chokes can sometimes kill high frequencies and transients. This seems plausible if their effect somehow extends down into the audible frequency range (or a little higher), and I don't know what it'll take for that to happen. Experiment with various locations and see. You may find they make no difference at all. I was recently struggling with an RFI problem and a choke on the power umbilical cable (from the power supply box to the preamp box) made absolutely no difference.
     
  3. Chu Gai

    Chu Gai Lead Actor

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    Rather than suggest a particular website, run a google search on the terms ferrite beads choke rfi and browse through some of the hits.
     
  4. Brian OK

    Brian OK Supporting Actor

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    Tim,

    IME, your best bet is to forget putting chokes/RF Stoppers on any of your components cables (except perhaps power cords) and put it on ALL the offending devices in your home which are generating perhaps all of the line hash you are trying to combat.

    Place them on the power cords for the following for best results:

    fridge, halogen lamp, baby monitors, cell phone charger wall wart, PC (desktop and notebook), 2gh/900mgh portable phone wall warts, cheap electronic wall warts devices (kids stereo... etc). If you can unplug any of these devices before you power up your HT then you are ahead of the game.

    Wall wart power suppies basically spew line hash and generate all sorts of interference. If you can add decent quality power conditioners on top of the chokes for these devices that would assist as well. And Audioprism Quietline parallel Line Filters on these outlets helps above and beyond too.

    Also dedicated circuits are the optimum for your system if you can swing it. Not to mention the use of a fine line
    conditioner. Balanced power is another quantum step as well. Battling RF starts outside of your system in a lot of cases.
    One really needs to address the AC before you start putting band-aids on your cabling.

    I tried RF chokes a few years ago and now they are all on the offending devices in my home, with positive results.

    Good Luck,


    BOK
     
  5. Chu Gai

    Chu Gai Lead Actor

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    I think that's a good idea Brian and with a bit of judicious shopping, relatively inexpensive.
     
  6. Timber

    Timber Stunt Coordinator

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    Thanks for all the replies guys. So far I've tried putting them the power cords of my receiver, TV, DVD and subs. All with minimal effect. I also have a separate amp with a horrible hum(at the amp, not the speakers) that I'll try.
    Brian,
    I'll give your suggestion a try next, as I know my house has plenty of wall warts. I think my HT room is on a circuit with one other room(bedroom) and not much is in that bedroom. Now if I could just find one big enough for my air conditioning unit[​IMG].
    Tim
     
  7. Brian OK

    Brian OK Supporting Actor

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    Tim,
    If you have fixed cords for your TV monitor and your receiver, I would recommend the Highwire Power Wrap. Your can find it for $24.99 ea. at www.amusicdirect.com
    As the listing states... "a very cost-effective tweak that reduces RFI. A helically-coiled strand of insulated metal-composite RF suppression material (not ferrite), this unique accessory wraps around your power cord......... We found that the PWrap was most effective on fixed power cords" .... also a model available for interconnects (two wraps provided) for the same $24.99.
    I use two of these in my system (processor and RPTV) and have found them to be very effective. Especially on the RPTV.
    Not dirt cheap, but a managable tweak if you are intent on results.
    I also unplug my CD player whenever I want to listen/watch the HT. I found it is amazing what hash the idle (yep, I shut it off, mind you ) CDP injects into the line, through my line conditioner, and into my RPTV's power cord. That mosquito noise forever present on my RPTV, however faint, literally dissapears altogether when the CDP is unplugged from the line conditioner. Those switching power supplies found in consumer grade DVD and CD players are a real enemy. Something to consider.
    BOK
     

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