PSN-L Email List Message

Subject: those strange jumps
From: "John Tacinelli" John.Tacinelli@........
Date: Tue, 25 Jul 2000 15:54:01 -0500

HI again,

I am overwhelmed with good ideas! Thank you all so much.  I will try do =
deal with each.  First of all the line voltage.  I have not checked this, =
however since the UPS showed the same problem, I don't think it is the =
line voltage.  I called the utility company and they said there were no =
shifts related to capacitors at that time.  They said there was a shift in =
usage around that time but they couldn't be very specific.  I'm pretty =
sure its not a joke, our students are not that bright....  I thought about =
streetlights but each is on its own photo cell and so they come on =
irregularly.  I did not have the seismograph running during the time =
change so I don't know if it tracks.  We are decidedly not in the desert =
here in Minnesota so I doubt it is the building heating and cooling, =
besides, this is too regular for something like that. =20

I like the idea put forward by Charles and Bob about AM radio interference.=
  I called around and there are two radio stations that have restricted =
licences.  One goes off the air at 8:45 and back on at 5:45.  Very =
interesting.  The other station changes power level from 5000 to 1000 =
watts at about that time.  They couldn't be more specific.  The station =
that goes off air says that I could shield the coil with grounded aluminum =
foil.  So I took the box that I use as an air cover and taped aluminum =
foil all over it.  I attached a wire to it with electrical tape and =
modified a regular AC 3-prong plug so that only the ground plug was there. =
 I attached the wire and plugged it into the  power strip for the =
computer.  The trace that had been going more or less down the middle, =
shifted to the left side of the screen.  So it seems to be doing something.=
  Tonight I will watch the thing again, this time with the shield in place =
and two radios going.  If it happens again I'll see if it coincides with =
the radio sign-off ( or signal decrease).  Also , the radio station =
changes its on-off times monthly so I can also see if it changes at the =
end of the month.  I am hopeful and will keep you all informed.  Thanks =
again for the help.

John Tacinelli
Earth Science Instructor
Rochester Community and Technical College


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Larry Cochrane <cochrane@..............>