[RFI] Snap-on RFI suppression core size vs cable size

N1BUG paul at n1bug.com
Mon Aug 21 10:47:34 EDT 2017

On 08/20/2017 10:34 PM, Jim Brown wrote:
> One turn will work fine. Although I haven't done any measurements to
> confirm it, I wouldn't worry about the loose fit.  Check out this data
> sheet  and note the plot of Z for 1-3 turns at the bottom of the page.
> For a 6M choke, I'd use two turns on a core, placing multiple 2-turn
> chokes in series along the cable.  That's NOT two turns through multiple
> cores in series, but two turns through core #1, then a short length (an
> inch or less) of coax and another two-turn choke, and another.

In solving receive noise problems on 6M I have done just that after 
looking at the Fair-Rite data sheets: two turns per core with 
multiple chokes in series as needed. It worked well.

It has been many years since I made a serious effort to deal with 
receive noise on 2M and back then it was a haphazard approach using 
whatever I had on hand. I have little or nothing on hand this time 
so I am trying to make sensible purchasing decisions.

Paul N1BUG

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