EMC measurements

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Finn Hammer by way of Terry Fritz <twftesla-at-qwest-dot-net>" <f-hammer-at-post5.tele.dk>

Gang!

As you all remember, I promised you some EMC measurements from the
Museum coil about a year ago, and they are now available after measuring
on 21-10-01.
Http://home5.inet.tele.dk/f-hammer/tesla/tesla.htm

The files disclosing details are uploaded to Terry`s site at :
http://hot-streamer-dot-com

At least that is what I think they are........

and called:

http://hot-streamer-dot-com/temp/Hor_10m.doc
http://hot-streamer-dot-com/temp/Ver_10m.doc
http://hot-streamer-dot-com/temp/BG_Ver_10m.doc

The coil was producing 6 feet streamers during the measurements,l for a
full one hour.

An attempt to explain the measurements is made:

The green graphs are for reference only, what you want to refer to is
the red X ès, which represent Quasi-peaks. It is these red Xes that you
should relate to, as compared to the red limit-line at the bottom.
A quasi-peak measurement is made, to reduce the measuring time from 1S
to 0,01S (the total measurement took 20 minutes each!)
We did reference measurements in a narrower frequency band, which showed
good correlation to the QP measurements, verifying that QP measurements
are useable for this application.

BG_Ver_10m
Vertical measurement (the antenna is in a vertical orientation) with the
coil shut up. Background noice measurement.

Ver_10m
Vertical measurement with the coil operating. Shows EMC exeeding the
legal limit by 70db at 30MHz and up to 30db at 1GHz

Hor_10m
Horizontal measurement with the coil operating. Shows emission up to
50db at 30 MHz and up to 40db at 1GHz.

Since both measurements need to be satisfied, this means that the
Faraday cage has to decrease the emission by 
70db at 30MHz
40db at 1GHz

I`l get back when more measurements are made.

Cheers, Finn Hammer