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
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