[RFI] TV RFI - an update 2

[Jim Brown]

On Wed, 13 Feb 2008 17:58:55 -0800, rrath at charter.net wrote:

>About the pin 1 issue. This VCR and TV only have a 2 wire cord, so no 
>ground. 

The chassis and circuit common of the VCR and TV have capacity 
coupling to the power system ground via the power transformer (and 
bypass capacitors), even if they have no green wire ground. So pin 1 
problems are likely to be there, and ARE a primary coupling mechanism, 
whether there's a 2-wire or 3-wire power cord. 

>The torroids I bought from Palomar were the T-200 model 120. This is
>their mix 2, which is for .25 to 10 MHz.

"Mix 2" is a disguise so they can sell it for 5-10X what Fair-Rite 
(the mfr) charges. I'll take a wild guess and say "mix 2" might be 
Fair-Rite #73 or #78 (I'm not looking at data, only the .25 to 10 MHz 
statement.) Both should work on 80M -- IF you wind at least 10 turns 
around it -- but they won't do much above 80.  

>I remember reading some thing about two wire cords in Jim Browns 
>60 pages about RFI. I will go back and re-read it. 

At the risk of being a PITA, I suggest that you STUDY it. These are 
difficult concepts to grasp. This is pretty much brand new stuff that 
took me years and a lot of work to figure it out. :)

Of course, the root cause could be lousy shielding in the VCR and/or 
TV, in which case you need the bucket treatment. :)

73,

Jim Brown K9YC