On 9/28/2020 7:23 AM, Cianciolo, Paul, W1VLF wrote:
In addition I have a Corcom 25fc10 installed at my home. See the data sheet
and response curves here.http://www.farnell.com/datasheets/1430489.pdf
The filter makes a barely detectable change in the any received RFI I have from
the SE system.
Hi Paul,
Conventional line filters are often ineffective against RF noise coupled
onto power wiring because the noise current is usually on the Green
wire, and the Green wire passes through them. These filters are actually
two differential filters applied to the Phase and Neutral conductors
plus a common mode filter applied to Phase and Neutral. They affect only
what's conducted to Phase and Neutral.
That current gets onto the green wire because it is not terminated
properly within the noisy equipment. It's the Mains Power equivalent of
what engineers in the pro audio world call "the Pin One Problem."
This is why common mode chokes formed by winding multiple turns of all
three conductors around suitable ferrite cores suppress common mode
current, while conventional line filters fail to do so. For suppression
at HF, Fair-Rite #31 material is the weapon of choice. Indeed, what EMC
regulations call common mode is not what we as radio engineers would
call common mode!
http://k9yc.com/Pin_1_Revisited.pdf
http://k9yc.com/Pin_1_Revisited_Part_2.pdf
http://k9yc.com/KillingReceiveNoise.pdf
Your photos didn't come through -- this reflector is plain text only.
73, Jim K9YC
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