> Subject: Re: unusual Jan 12 quake near Bermuda?
> From:    The Lahrs 
> Date:    Mon, 14 Jan 2002 20:56:05 -0700
>
> David,
>
> I'm very impressed by your system!  You've got a good recording
> of the Bermuda event.

Thanks, but I think a quirk of nature had a lot to do with it.  Here is
some long and short period data from LCSN-PAL in NY:
http://www.infiltec.com/seismo/020112pl.gif long period data image
http://www.infiltec.com/seismo/020112ps.gif short period data image
This quake delivered a lot of seismic energy at high
frequencies to the east coast of the US.

>Have you done an FFT in WinQuake to
> see what the predominate frequency of your signal is?

Yes, I often use the WinQuake FFT for debugging my hardware
Here is the quake FFT and the data file
http://www.infiltec.com/seismo/020112a.gif quake data image
http://www.infiltec.com/seismo/020112af.gif quake fft image
http://www.infiltec.com/seismo/020112a.set quake data
And here is typical background noise FFT and data file
http://www.infiltec.com/seismo/020112n.gif noise data image
http://www.infiltec.com/seismo/020112nf.gif noise fft image
http://www.infiltec.com/seismo/020112n.set quake data

The low pass 8 pole bessel filter chip allows me to
reduce the sampling rate to about 4.5x the low pass
cutoff and still not get much aliasing.

> I really like your idea of making an inexpensive system, as
> cost is a major limitation for most teachers.  Are you going
> to make a long period version as well?

Yes, the same board works for my long period Lehman.  All
I have to do is change some a couple of capacitors and
resistors to reconfigure it for 1 Hz or any other low pass, plus
similar changes for the sensor (coil) characteristics.  The microprocessor
is programmed so that is can be switched between several
sampling rates between 5 to 23.7 SPS.

Here is the noise spectra
from my Lehman system using a 1 Hz lowpass
http://www.infiltec.com/seismo/010129f.gif noise fft image
http://www.infiltec.com/seismo/010129n.gif noise data image
And here are some teleseismic events
http://www.infiltec.com/seismo/010113a.gif  8m quake image
http://www.infiltec.com/seismo/010126a.gif ? quake image
but I have erased the .SET files, so no FFT.  My Lehman
has been down for repairs for a few months so I do
not have any current data from it.

> Maybe you should check
> out Meredith's levitated-graphite design as an alternative to
> a large Lehman-style swinging-gate sensor.
>
> What is involved and how difficult is it to program the PIC14000
> computer?

I program them in PicBasic Pro with a $400 system from www.mplabs.com.
You can take a course on programming them in C from www.phanderson.com
The PIC14000 is a little trickier than some of the other PICs that
have onboard A/D, but it is the only one with 16 bits.
I have more microprocessor resources on my web page
http://www.infiltec.com/seismo/#micro

> Are you planning on providing do-it-yourself instructions
> for your electronics?

That is the plan. All I need is some extra time...

Ciao,

Dave Saum



----- Original Message -----
From: 
To: 
Sent: Wednesday, January 16, 2002 3:01 AM
Subject: Digest from 01/15/2002 00:01:41


>
> .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> | Message 1                                                           |
> '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> Subject: Can't connect to PSN web page
> From:    RLLaney@.......
> Date:    Tue, 15 Jan 2002 13:35:55 EST
>
> I have been unable to connect to the PSN web page for the past 3 days.  Is
> the system down, or is anyone else having a similar problem?
>
> Thanks.
>
> Bob Laney
> Herndon, VA
>
>
> .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> | Message 2                                                           |
> '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> Subject: Re: Can't connect to PSN web page
> From:    "Larry Cochrane" 
> Date:    Tue, 15 Jan 2002 14:02:52 -0800
>
> Bob and Others,
>
> At first I thought the PSN.QUAKE.NET domain name finally went away. This
was
> my old domain name when I first got onto the Net. QuakeNet is now out of
> business but still has a DNS server up and running with the PSN.QUAKE.NET
> domain pointing to one of my DNS lines. I know that someday this domain
name
> will go away since I have no control over it. I thought that that time has
> finally happened.....but after doing some more checking, it turn out that
my
> PacHell DSL line was down. This is my backup DSL line so I don't monitor
it
> very often. After doing some more checking I found a loose wire outside in
> the phone line junction box attached to the house. Reconnecting the wire
> fixed the problem so everything should be back to normal. Thank God, I
> didn't want to spend the next 3 hours on hold waiting for someone at
PacHell
> too talk to.
>
> If the PSN.QUAKE.NET domain name stops working just start using
> WWW.SEISMICNET.COM.
>
> -Larry Cochrane
> Redwood City, PSN
>
> ----- Original Message -----
> From: 
> To: 
> Sent: Tuesday, January 15, 2002 10:35 AM
> Subject: Can't connect to PSN web page
>
>
> > I have been unable to connect to the PSN web page for the past 3 days.
Is
> > the system down, or is anyone else having a similar problem?
> >
> > Thanks.
> >
> > Bob Laney
> > Herndon, VA
> > __________________________________________________________
> >
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> >
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> >
>
>
>
>
> __________________________________________________________
>
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>
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