[Elecraft] Plasma TV Noise any ideas on how to filter it out.

[Stewart]

On Wed, 11 May 2011 09:34:05 -0700, Jim Brown wrote:
> On 5/10/2011 7:49 PM, Jim Wiley wrote:
>> You guys are aware, I suppose, that interference of this level and
>> duration clearly qualifies as  the type of interference that merits
>> direct FCC intervention.  File a complaint.
>
> Absolutely. We are right and they are wrong.  If we "lay down," we have
> only ourselves to blame.
>
> One suggestion though for suppressing the RF trash.  While I (so far)
> have no experience with Plasma TV RFI, MOST RF trash from electronic
> products, especially the stronger part of it)  is radiated as a common
> mode signal by wiring both inside and outside the product. We can't do
> anything about the wiring inside the product, but we can kill the RF
> current on the EXTERNAL cables that connect to it, like the power cable,
> the coax cable(s), and any audio and video cables.
>
> To kill RF current on ANY cable, form a common mode choke by winding
> turns around a ferrite toroid (or clamp-on). 14 turns on a #31 2.4-in
> o.d. toroid is about right for 1-10 MHz, and 8 turns on a 1-in i.d.
> clamp-on.  For the higher HF bands (14-30 MHz), use 8 turns around the
> toroid (either #31 or #43 mix) and 5 turns through the clamp-on. Use a
> separate ferrite core for each choke. If you have trash on all the
> bands, use both chokes on each cable.
>
> This may or may not help, and it certainly won't help the part of the
> trash radiated by internal wiring,  but if I had RFI from a plasma set,
> I sure would try it before throwing up my hands.
>
> Lots of detail, including the technical explanations of why this works,
> is in
>
> http://audiosystemsgroup.com/RFI-Ham.pdf
>
> 73, Jim Brown K9YC

Fine if it's your set. Not so easy if it's an obstinate neighbour...

73
Stewart G3RXQ
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