> On Apr 24, 11:08 pm, Robert Macy <robert.a.m...
> > On Apr 24, 4:18 am, pault <pau...@gmail.com> wrote:
> > > 5khz is in the VLF band (also in the human hearable audio band)
> > > This looks like a suitable VLF receiver circuit:
> > > (Magnetic Pickup) athttp://www.spiro.fisica.unipd.it/~mbarbisa/espfis/VLFwhistle.htm#Magn...
> > > you probably dont need the second op amp and should feed the output
> > > into
> > > a tone decoder pll like the lm567
> > > an even simpler circuit on the same page might work too
> > > (Super-Tiny VLF Receiver)http://www.spiro.fisica.unipd.it/~mbarbisa/espfis/VLFwhistle.htm#Supe...
> > > seehttp://www.scary-terry.com/more_stuff/tonedet/tonedet.htm
> > > for an example lm567 circuit
> > Thank you for these URLs!
> > I didn't see any mention of Chernov Radiation being a source of VLF.
> > It is my understanding that as a cosmic particles enter our atmosphere
> > they slows down, thus giving off energy, called Chernov Radiation. I
> > understand that the effect is greatly enhanced by using a tank of
> > water to slow the particles down and using photon multiplier tubes to
> > 'view' the light trail these particles give off. Japan has a cave
> > lined with some 1,000+ multiplier tubes [at $20,000 each that's
> > impressive!]
> > Further by calculating the information from the light trails it is
> > possible to determine energy/origin essentially making a form of
> > telescope that can look deep into space. Note: the cave setup in Japan
> > went through an unexplained failure mechanism where by they lost
> > almost ALL tubes, going off like a popcorn string. They had to drain,
> > replace, only to lose them again.
> > There was a Professor in New Mexico who contended that by measuring
> > VLF, you could surmise the Chernov Radiation of these particles as
> > they went through the atmosphere, thereby making a much cheaper form
> > of telescope. I designed the magnetic VLF receiver with noise floors
> > 50X less than earth's field's noise floor and I got to add the concept
> > of placing many such VLF receivers spaced every so far along the US,
> > for 1000's of miles, essentially a phased array antenna. The end
> > result would be creating an extremely wide lense telescope capable of
> > looking deeper into space than man has ever looked in his history.
> The Stanford University VLF Group (http://vlf.stanford.edu/) may
> be involved in that area of research
> theres an interesting vlf page here (http://www.vlf.it/ )
> and a yahoo discussion group (http://tech.groups.yahoo.com/group/VLF_Group/