[RFI] Direct TV DVR problems

[Jim Brown]

On 11/2/2010 10:52 AM, Howard Lester wrote:
> Tom, start here at the Fair-Rite site.
>
> http://www.fair-rite.com/cgibin/catalog.pgm#select:where4
>
>   Click on the big blue buttons for Suppression, then Cables, then either
> Round Cable EMI Cores or Round Cable Snap-Its, and find #31 material. The
> chart seems to default to #31, but there are tabs at the top of the chart
> where you can select other types of material.

That catalog is a great reference, far better than any of their 
competitors.
>   I see that
> #2631803802 (second from the bottom) is the size I referred to above. It's
> 2.40" O.D.

This is an EXCELLENT all purpose part for use on the HF bands.  Some 
re-sellers call it FT-240.

> There's one more size larger: 4" O.D.

This is much bigger than is needed for most purposes, and will be a lot 
more expensive and hard to find because it's not widely used (and thus 
not in stock from vendors with good prices).
>   In general, you just want
> to get as many turns as possible through the toroid, so you have to take
> into account the size of your various cables' end fittings

Not quite -- it depends on the operating frequency.  See 
http://audiosystemsgroup.com/RFI-Ham.pdf

73, Jim K9YC