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.
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.