From: Marco Denicolai
Date: Thu, 01 Nov 2001 09:06:40 +0200
Subject: Re: [TSSP] EMI measurements
Hi Finn,
so the third graph is just background noise...Well, that explains my
doubts and also turns them down.
Still, if you are going to measure the TC again, maybe you could also do
one extra scan without streamers. I bet the difference in the emission
spectrum could be interesting.
Best Regards
Finn Hammer wrote:
>
> Marc!
>
> Are you sure you are not talking about the file that you access from the
> bottom link?
>
> http://hot-streamer.com/temp/Hor_10m.doc
> http://hot-streamer.com/temp/Ver_10m.doc
> http://hot-streamer.com/temp/BG_Ver_10m.doc
>
> Because what it shows is the background noise at the testsite. (the
> antenna is looking right into a 12MW hydroelectric plant (built in the
> 1920`s), some 150 meters away, through an accompanying HV substation.
>
> The 2 top links point towards the coil working.
>
> I asked the director of the museum, if we could make another set of
> measurements,(he foots the bills) but he is a bit reluctant to do so.
>
> However, when the faraday cage is in place, we will make another set of
> measurements, and by then, the spark gap will be situated inside it`s
> own metal shielding box.
>
> It would be nice to have a field day with this equipment, but the money
> is better spent elsewhere, since our budget is limited.
>
> Cheers, Finn Hammer
>
> Marco Denicolai wrote:
> >
> > Hi Finn,
> >
> > For instance, the requirement for the modems I design at work (SHDSL,
> > SDSL, HDSL, etc.) is EN 55022 (for radiated emission). We use a Rohde
> > &Schwarz ENY22 ISN spectrum analyser, which I bet is pretty the same
> > than what you used. The limits are similar to the ones in your plot.
> >
> > For a curve comparison, see
> >
> > http://www.iki.fi/dncmrc/work/modem.jpg
> >
> > This is a 8 x 2Mbps HDSL modem board, consuming 10W of DC power.
> >
> > I mean, I don't see such a big difference in the quality of the
> > emissions, maybe some 10 dB more in the TC case. What about if you had
> > been measuring the TC without producing streamers? I guess then we would
> > see it in the radiated emission graph (but then it would be useless to
> > qualify you for being "museum compatible").
> >
> > Do you think you could repeat the measurement with a lower voltage or a
> > bigger toroid (and no streamers)?
> >
> > Best Regards
> >
> > Finn Hammer wrote:
> > >
> > > Gang!
> > >
> > > I posted this info to the pupman list, but for some reason it did not
> > > seem interesting.
> > > However, I think that the first public measurements of a Tesla coil`s
> > > electromagnetic radiation just has _got_ to be interesting, so in the
> > > light of this lists longlasting quietness, I allow myself to break the
> > > silence and tell you:
> > >
> >
> > > Cheers, Finn Hammer
> >
> > --
> > _____________________________________________________________
> >
> > Marco Denicolai Senior Design Engineer
> > Tellabs Oy tel: +358 9 4131 2769
> > DSL Products mobile: +358 50 353 9468
> > Sinikalliontie 7 fax: +358 9 4131 2410
> > 02630 Espoo FINLAND email: marco.denicolai@tellabs.com
> > _____________________________________________________________
--
_____________________________________________________________
Marco Denicolai Senior Design Engineer
Tellabs Oy tel: +358 9 4131 2769
DSL Products mobile: +358 50 353 9468
Sinikalliontie 7 fax: +358 9 4131 2410
02630 Espoo FINLAND email: marco.denicolai@tellabs.com
_____________________________________________________________
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.