PSN-L Email List Message

Subject: "P" ky "Slinky"
From: tchannel1@............
Date: Thu, 26 Jul 2007 09:51:58 -0600


Hi Folks,   In the past I have asked the group questions about various =
designs.  I have made several sensors, some of no value and some which =
work well for me in this location.   We all learn from doing.  I really =
like the simplicity of the AS-1, but the cost keep me from purchasing =
one, and started my efforts to make one from items I could get locally.  =
 I also wanted to get kids involved in a project which would not require =
a machine shop.   My Grandkids in Alaska enjoyed their project for a=20
science class.

One thing I could not do, was to build the Amp/Filter, I did try and got =
the board working by not good enough.
I solved that Big issue by purchasing Larry's board, which worked great.

I think it was the sixth sensor I dubbed   "P" ky-"Slinky"   The idea =
was to hang a long spring from the ceiling 7' overall.  On the end of =
the spring a magnet moving in and out of a coil.   Add a damper, and =
enclose it.
A little like a very long geophone.

I did a prototype and it worked.  So I built one for real,  I started =
using 7'  which included the entire unit.  I later changed it to =
5'...........I thing the period is about 2.2 seconds.  I made a few =
modification and it has been trouble free and recording earthquakes from =
all over the world, and in greater numbers than my Lehman.   Obviously =
not with all the phases, one would expect with a longer period sensor.

The spring, perhaps the one at the bottom of the list of appropriate =
choices, is working just fine.   I see no temperature noise, although it =
must be there, and since the spring is in a tube I don't get air =
currents.   The only issue I had with the spring is that it stretched =
about one inch over one month, and now has stopped.

I did not keep track of the cost, but I think it was maybe $50 - $75 =
including everything for the sensor.   For a full station one would need =
all the other things, like the Amp/Filter, AD converter, cables Software =
and an old computer, etc.

I am now operating this unit and posting the recordings as TCIDzs  as =
z-vertical s-slinky.   At night time the noise level is very low, during =
the day the noise level is high, due to road construction.  On the week =
end the noise level is low.


http://picasaweb.google.com/tchannel33   I have posted some picture =
here.  Just click on the album call "5' Slinky"
and you can see 9 pictures,  I hope.  Notice one shows the tube 7' tall =
and one 5' tall, after I modified it.

This is an inexpressive unit, using simple materials, little machine =
work, fun..........and I am please with its performance.
Email me if you want to make one,  and I will give you details.  I can =
sent or post .gif images of its recordings as well.

It just a fun and easy project.     tchannel1@............

Ted














Hi Folks,   In the past I = have asked the=20 group questions about various designs.  I have made several = sensors, some=20 of no value and some which work well for me in this = location.   We all=20 learn from doing.  I really like the simplicity of the AS-1, but = the cost=20 keep me from purchasing one, and started my efforts to make one from = items I=20 could get locally.   I also wanted to get kids involved in a = project=20 which would not require a machine shop.   My Grandkids in = Alaska=20 enjoyed their project for a
science class.
 
One thing I could not do, was to build = the=20 Amp/Filter, I did try and got the board working by not good = enough.
I solved that Big issue by purchasing = Larry's=20 board, which worked great.
 
I think it was the sixth sensor I=20 dubbed   "P" ky-"Slinky"   The idea was to hang a = long=20 spring from the ceiling 7' overall.  On the end of the spring a = magnet=20 moving in and out of a coil.   Add a damper, and enclose=20 it.
A little like a very long = geophone.
 
I did a prototype and it worked.  = So I built=20 one for real,  I started using 7'  which included the entire=20 unit.  I later changed it to 5'...........I thing the period is = about 2.2=20 seconds.  I made a few modification and it has been trouble free = and=20 recording earthquakes from all over the world, and in greater numbers = than my=20 Lehman.   Obviously not with all the phases, one would expect = with a=20 longer period sensor.
 
The spring, perhaps the one at the = bottom of the=20 list of appropriate choices, is working just fine.   I see no=20 temperature noise, although it must be there, and since the spring is in = a tube=20 I don't get air currents.   The only issue I had with the = spring is=20 that it stretched about one inch over one month, and now has=20 stopped.
 
I did not keep track of the cost, but I = think it=20 was maybe $50 - $75 including everything for the sensor.   For = a full=20 station one would need all the other things, like the Amp/Filter, AD = converter,=20 cables Software and an old computer, etc.
 
I am now operating this unit and = posting the=20 recordings as TCIDzs  as z-vertical s-slinky.   At night = time the=20 noise level is very low, during the day the noise level is high, due to = road=20 construction.  On the week end the noise level is low.
 
 
http://picasaweb.google.c= om/tchannel33  =20 I have posted some picture here.  Just click on the album call "5'=20 Slinky"
and you can see 9 pictures,  I = hope. =20 Notice one shows the tube 7' tall and one 5' tall, after I modified=20 it.
 
This is an inexpressive unit, using = simple=20 materials, little machine work, fun..........and I am please with its=20 performance.
Email me if you want to make one,  = and I will=20 give you details.  I can sent or post .gif images of its recordings = as=20 well.
 
It just a fun and easy=20 project.     tchannel1@............<= /DIV>
 
Ted
 
 
 
 
 
 
 
 

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