[RFI] 40M TVI problem

Jim Brown jim at audiosystemsgroup.com
Mon Nov 13 11:50:42 EST 2006

On Mon, 13 Nov 2006 09:12:17 -0800 (PST), SERGE BERTUZZO wrote:

>Any assistance/guidance would be greatly appreciated.


See the tutorials, with measured data, for ferrite chokes in several 
common and useful configurations at the link above. What you 
probably need is a choking Z of at least 2-3K ohms. Referring to the 
data, a choke with 10-12 turns around a #43 or #31 2.4 toroid 
(commonly called FT-240-size by resellers) should do the job -- IF 
the RFI is coming in on the downlead. If it is getting in other 
ways, you may need to do more. For example, if its coming in on the 
power line, you may need a choke (like the first one) on the power 
line. If its bad shielding, youre probably stuck with the bucket 
treatment. ****

**** The bucket treatment. Find a bucket large enough to hold the 
offending TV, and fill it with water. Put the TV in twice. Take it 
out once.

Jim Brown K9YC

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