[RFI] TV RFI - an update

[Jim Brown]

On Wed, 13 Feb 2008 12:46:23, Hardy Landskov wrote:

>I have never solved a VCR interference problem. Solution: I don't operate
>when the VCR is on. 

The most common path for HF RF into a VCR is common mode current on the 
antennna leadin coupling via a "pin 1 problem" in the VCR. This is 
especially true on the lower HF bands. Study the section in my RFI tutorial 
about choking common mode current and you'll solve these problems. Hint: A 
good starting point is a serious multiturn toroidal choke on the antenna 
feedline to the VCR, and may also require chokes on other leads. Especially 
on the higher HF bands (20-10), shorter leads (audio and video 
interconnects) may excite a "pin 1 problem." 

http://audiosystemsgroup.com/RFI-Ham.pdf

Obviously, other cables may also couple RF, and there can also be shielding 
problems, but the MAJOR coupling for the lower HF bands is the "pin 1 
problem." 

73,

Jim Brown K9YC