[Prev][Next][Index][Thread]

interference




----------
From:  Steve Young [SMTP:youngs-at-konnections-dot-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-at-allcorp-dot-com, and their URL is www.allcorp-dot-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-at-next-wave-dot-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-at-next-wave-dot-net
> 
> 
> > From:  Julian Green [SMTP:julian-at-kbss.bt.co.uk]
> > Sent:  Sunday, June 14, 1998 6:24 AM
> > To:  tesla-at-pupman-dot-com
> > Subject:  Re: interference
> > 
> > > From:  D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-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-at-next-wave-dot-net
> > > 
> > > 
> > 
> > Tried that - no joy.   More 2am coiling for me then.
> > 
> > Julian Green
> > 
> 
>