Dave-
Any details or pictures on your three lines of the main CM choke?
One choke for each line?
A simple multiple wrap of the power cord?
Thanks,
AG6CX
Sent from my iPhone
> On Feb 18, 2022, at 3:19 PM, David Eckhardt <davearea51a@gmail.com> wrote:
>
> An effective common mode choke on the mains conductors should pass all
> three conductors through the core. For a 2.4-inch OD core, three turns are
> usually good. Too many more will increase the capacitive coupling. 31
> material has an advantage at the lower frequencies where the older 43
> material is a bit better at higher frequencies. All referring to HF.
>
> I have "solved" many an emissions problem usually around 40 to 70 MHz from
> SMPSs by simply installing a simple common mode choke on the mains lines
> (yes, all three lines: hot, neutral, and "ground" - the green wire). Once
> these products reach a contract manufacturer, the common mode choke adds
> nothing to performance and only adds cost, so it is removed. Many times I
> ran into the reality that contract manufacturers are the EMC engineer's
> worst enemy. They are supplsed to retest and re-qualify, but they don't.
>
> Dave - WØLEV
>
>> On Fri, Feb 18, 2022 at 10:51 PM Jim Brown <jim@audiosystemsgroup.com>
>> wrote:
>>
>> Thanks Ed. What ferrite mix and how many turns?
>>
>> 73, Jim K9YC
>>
>>> On 2/18/2022 12:53 PM, Hare, Ed, W1RFI wrote:
>>> We just obtained an AC line filter by Morgan Manufacturing. It also used
>>> a ferrite on the ground wire.
>>
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>
>
> --
> *Dave - WØLEV*
> *Just Let Darwin Work*
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