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interference




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From:  Steve Young [SMTP:youngs@konnections.com]
Sent:  Tuesday, June 16, 1998 9:55 PM
To:  Tesla List
Subject:  Re: interference

Julian, all:

All Electronics (in Van Nuys, CA) sells brand new surplus EMI filters rated
at up to 250 volts, 20 amps for $5 each.  Made by Delta Electronic
Industrial Co.  Their order number is 1-800-826-5432, E-Mail
allcorp@allcorp.com, and their URL is www.allcorp.com.  Dr. Resonance says
you can parallel EMI filters for more current capacity.  All Electronics
has other stuff of potential interest to coilers, such as .001 Mfd 10 KV
ceramic disk caps ($1) for HV RF filters.

--Steve


> From:  D.C. Cox [SMTP:DR.RESONANCE@next-wave.net]
> Sent:  Monday, June 15, 1998 11:31 AM
> To:  Tesla List
> Subject:  Re: interference
> 
> to: Julian
> 
> Corcom makes good 20 amp 220 volt filters.  Don't operate without them or
> your neighbors will hate you -- or report you and start the up trouble. 
> You can get used filters from Fair Radio Sales, Lima, OH, for a
reasonable
> cost.
> 
> DR.RESONANCE@next-wave.net
> 
> 
> > From:  Julian Green [SMTP:julian@kbss.bt.co.uk]
> > Sent:  Sunday, June 14, 1998 6:24 AM
> > To:  tesla@pupman.com
> > Subject:  Re: interference
> > 
> > > From:  D.C. Cox [SMTP:DR.RESONANCE@next-wave.net]
> > > Sent:  Friday, June 12, 1998 12:40 PM
> > > To:  Tesla List
> > > Subject:  Re: interference
> > > 
> > > to: Julian
> > > 
> > > You should run a pair of commercial RF filters in series -- 2 stage
EMI
> > > supression.  Also a 1 1/2 size ferrite toroid with aprox 2 turns on
> each
> > > leg of your power wires (hot and neutral) will help reduce any
> additional
> > > RF.  It's also a good idea to use a few varisters from each line to
> ground
> > > at the xmfr input power points.  This along with a 1 K, 50 watt
> resistor
> > > off each xmfr bushing will help to keep RF kickback into the power
> lines at
> > > a minimum.  
> > 
> > At present I dont use EMI supression units - I couldnt find anything
> large
> > enough.   My coil is pole pig powered and draws 13-15 amps when
running. 
> I
> > have no PFC caps either.
> > 
> > I was hoping that the 100meter extension lead that I use to power the
pig
> > would act as RF supression and balast.   A coiled externsion lead looks
> like 
> > this (I think):
> > 
> >  Live   >---OOOOOOOO--->
> >             --------      Load
> >             --------
> > Neutral >---OOOOOOOO--->
> > 
> > and has a DC resistance of 5 Ohms.   I see this circuit printed on the
> side
> > of RFI supression units.   
> > 
> > The radio walk test was conducted with the coil running at a 'safe'
power
> > level and no streamers.   The radio was tuned to 200KHz (same as my
> coil).
> > I walked roughly 50feet and the interference on the radio stopped -
this 
> > supprised me as I thought I had a long walk ahead of me.   When the
coil
> is
> > running with no spark breakout there is little or no interference on TV

> > reception.
> > 
> > >From the above tests do you think that the coiled extension lead is
> doing
> > OK, or should I setup better RFI supression?
> > 
> > I also have a question about PFC - how do you calculate/guestimate the
> value
> > of the cap needed?  (If I power up the pole pig with primary cap
> connected and
> > spark gap open the pole pig is drawing 4Amps.  Its a 5KVA unit 240V -
> 11Kv)
> > 
> > > Don't forget to invite your neighbors over for a free BBQ
> > > sometime soon -- if they understand what you are doing and think your
> work
> > > is "cool" they are not so likely to think of you as a "geek" whose
sole
> > > intent is to destroy their TV reception while they are watching their
> > > favorite prime time shows -- and be sure to find out when they watch
> the
> > > most and don't run during those times.  Trying hard to be a "good
> neighbor
> > > with an interesting hobby" goes a long way towards reducing the
> > > neighborhood pest syndrome.
> > > 
> > > DR.RESONANCE@next-wave.net
> > > 
> > > 
> > 
> > Tried that - no joy.   More 2am coiling for me then.
> > 
> > Julian Green
> > 
> 
>