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Re: RF Interference : HELP!!!
<BIG SNIP>
Ricahrd -
>Ouch!
>
>It sounds like you have undertaken the basic measures to prevent
>excessive RFI, but you are still leaking. My guess is that
>somewhere, somehow, you have significant RF current leaking into
>your 60 cycle ground. This can/will energize the grounded
>sections of etched circuit boards (TV, radio, computer, etc). The
>60 cycle neutral wire and the 60 cycle ground wire are most
>likely commoned in your building (they are in mine): direct,
>unfiltered/unchoked connections between your RF ground and the
>building-ground/neutral wire will cause this problem. Look here
>first by checking continuity between the building neutral/RF
>ground with a meter. If you show a direct connection between the
>60 cycle neutral and your RF ground then you must isolate this
>connection and either remove it or place a filter/choke between
>the two circuits to reduce RFI.
>
>Richard Hull just posted here in the last week or so that RFI/EMI
>filters can be run with any orientation. My CORCOM filters (No.#
>F2411F) clearly depict an RF choke in the ground path. I choose
>to place my filters and ground my equipment in such a fashion
>that ground path contaimination is not a problem. With these
>filters it is possible to place the integral RF choke in the
>ground path in such a way as to prevent a low RF impedance
>between ground paths. By physically and electrically isolating my
>grounds I maintain a very clean 60 cycle ground/neutral wire that
>can be used without a problem during low power (>2kVA) operation.
>
>Even without any RF filters or chokes I have run coils up to 1
>kVA without a problem by ensuring an electrical separation
>between the RF ground and the 60 cycle ground.
Did you ever notice the meter slowing down when the coil runs? I think it
is prevalent in "noisy" circuits like mine that don't have a good RF ground
and are using the mains as ground. That will also introduce some RF on the
power lines and I don't think the hams like that one! ;-)
Less devices to soak up that power, though. Is that how Tesla blew the
generator in Colorado Springs? Or didn't he use fuses? Did he use fuses?
Some of his safety methods seem frightening to me by todays standards (i.e.,
OSHA).
Later,
*** Magic Bill ***