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(meteorobs) VLF Detector
-------------------- Begin Original Message --------------------
Message text written by INTERNET:meteorobs@jovian.com
"Some years ago, there was a short article in Meteor News with the plans on
building a very simple looking VLF detector for fireball generated
electrophonic noise. I don't know which issue? I had it around somewhere
and
just went thru everything at my house looking for it. It's most likely in
my
observatory. I will have to check the next time I go up there. Anyhow from
the directions, I built such a device at my observatory about a year ago. I
had intentions of hooking up the reception to my old long playing tape
recorder while I visually observed. The recorder would have been started at
a
specific time. The scheme was if I saw a bright fireball, I was gonna try
to
find any indications of electrophonic noise generated onto the tape from
the
recorder's amplifier. Like I said, my tape recorder is old (35 years) and
it
has some problems that I felt wasn't reliable enough to do what I wanted to
do, so I never used it. But the set up is designed to wear a headset or
hook
up to a tape recorder. Perhaps someone can find the article in meteor news
and make some use of the idea? I'm not sure which year it would be in....my
guess somewhere between 1992 and about 1996?
GeoZay"
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Hi George,
Note that is there is a difference between ELF (extremely low frequency )
and VLF (very low frequency ). I think McGreevey works at ELF frequencies
which are below 10kHz. VLF starts at around 10 kHz and goes up to 500 KHz
or so. (Please someone correct me if those figures aren't right.)
The dilemma in ELF monitoring is that 60HZ electric power line emission is
interference to ELF radio frequencies. ELF requires that you be at least a
half mile away from electric lines. Otherwise the receiver is saturated
with buzz.
---Tom Ashcraft
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