You brought it up Jim; and I can see how, given
the prescription for looping the neutral and just
one phase through 'the magnetic' back at the
source where this saturation problem that you
spoke of can become a problem; I simply gave
the cirumstances under which this can occur
Quoting J. Brown from earlier:
As to cores -- they are likely to saturate under
load if you put them on individual conductors, so
plan on putting them on the paired cable so that
the total field is small (that is, the hot is cancelled
by the return). Used this way, the cores will
attenuate common mode radiation from the line.
Simply placing a 'core' on either phase plus neutral
back at the source (we _were_ talking about suppres-
sing gen noise IIRC) results in a _full_ magnetic field
contributed by the single phase, during balance, with
little or no 'countering' magnetic is produced owing to
little or no current on the neutral at/near the gen. This
is really pretty basic stuff ...
A better location looks to be placement around both
hot-conductors, such that at least partial cancellation
of the field produced by the 60 Hz line current while
suppying common mode rejection to noise coming
from the gen would be achieved.
My choice? I'd buy a commercially rated filter and
escape all this napkin-based 'ballpark engineering'.
Jim P / WB5WPA /
---- Original Message -----
From: "Jim Brown" <jim@audiosystemsgroup.com>
To: "RFI List" <rfi@contesting.com>
Sent: Wednesday, March 23, 2005 11:07 AM
Subject: Re: [RFI] Honda Generator RFI
> On Wed, 23 Mar 2005 10:19:21 -0600, Jim P wrote:
>
> >It does/it can, if you saturate the particular magnetics
> >selected, by improper application, which was what I
> >was pointing out
>
> What magnetics are being saturated, and how? If all the current-
> carrying conductors are going through the ferrite choke, the net
> field is limited to the common-mode current, which ought to be the
> noise, unless something is broken (or shorted to a conductor that
> doesn't go through the choke).
>
> I wouldn't expect a power transformer to generate RF trash upon
> saturation. What else might I be overlooking?
>
> Jim
>
>
>
>
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