Brett, Dave, Chris,

Brett - Thanks for the nice comments on my new sensor. I have Kay and Chirs
to thank for the design.

Chris - I have reoriented the magnet block for the coil as you have suggest.
and, yes, I was able to close the magnet gap quite a bit since the arc of
the end of the boom no longer is a factor.

I understand your suggestion to move the music wire fasteners closer to the
edge of the two flanges. I might try using larger washers as you have
suggested to effectively shorten the length of the music wire. I can
visualize how this will help stabilize lateral movement of the boom.

I could not follow your AL can instructions. I guess I need more of a
visual for that to work with my lack of an imaginative mind.

Dave - I have uploaded new pictures with more detail of the hinge area.
Take a look and let me know if you need more detailed pics. Also I have the
plans in a PDF that I can send you that came from Kay. Or, maybe I can
upload them here?

Hope I didn't leave out anybody comments or questions.

Best,

Rich Schneider
KCMA - IRIS



On Fri, Nov 25, 2011 at 9:10 PM, Dave Nelson wrote:

> Hi Brett
>
>  Thats interesting, as I though because most manmade local noise is
> vertically polarised, the main one ... people walking around, then its
> going to be easier to pick up on the vertical seismo.
>
> well looks like I'm going to have to build one and see how it goes  :)
>
> Richard, any chance of a pic with a bunch of measurements on it please
> so I can get an idea of some dimensions of the various bits and close ups
> of the hinge section
> just email direct to me if possible
>
> thanks lots
> Dave
>
>
>
> At 08:50 AM 21/11/2011 -0500, you wrote:
>
>> Hi Dave,
>>
>> I agree, Richard has made a very nice looking instrument.
>>
>> Regarding noise, I think it's the other way around.  Generally the
>> verticals are considerably less sensitive to local disturbances of the
>> ground (though much more sensitive to temperature and barometric pressure
>> changes).  Here's a couple of traces captured from the vertical channel
>> (top trace) and one of the horizontal channels of a Nanometrics Trillium
>> Compact 120 three-axis instrument, operated by Dave Nelson in California.
>> http://bnordgren.org/seismo/H_**vs_V_-_Trillium_120.jpg
>> The wind was blowing that day and was shaking the ground quite a bit.
>>  That's typical of what you would normally see.
>>
>> Good verticals can be a lot harder to build, but they can perform much
>> better in the sorts of locations that are likely to be available.
>>
>> Although his instruments are located very close to the house
>> http://bnordgren.org/seismo/**IMG_1383s.jpg
>> Dave gets very good results with his verticals, whose traces
>> http://bnordgren.org/seismo/**gif_images.htm
>> can look as good or better than the USGS helicorder plots.
>> http://aslwww.cr.usgs.gov/**Seismic_Data/telemetry_data/**ANMO_24hr.html
>>
>> As we continue to test new designs, it appears that his vertical
>> instruments' sensitivity, as determined by their internal noise, may
>> possibly be a little better than his Trillium.  More testing in the works.
>>
>> Regards,
>> Brett
>>
>
>  ______________________________**____________________________
>
> Public Seismic Network Mailing List (PSNLIST)
>
> To leave this list email PSNLIST-REQUEST@.............. with the body of
> the message (first line only): unsubscribe
> See http://www.seismicnet.com/**maillist.htmlfor more information.
>
Brett, Dave, Chris,
=A0
Brett=A0- Thanks for the nice comments on my new sensor. I have Kay an=
d Chirs to thank for the design.
=A0
Chris - I have reoriented the magnet block for the coil as you have su=
ggest.
and, yes, I was able to close the magnet gap quite a bit since the arc=
 of the end of the boom no longer is a factor.
=A0
I understand your suggestion to move the music wire fasteners closer t=
o the edge of the two flanges. I might try using larger washers as you have=
 suggested to effectively shorten the length of the music wire. I can visua=
lize how this will help stabilize lateral movement of the boom.

=A0
I could not follow your AL can instructions. I guess I need more of a =
visual for that to work with my lack of an imaginative mind.
=A0
Dave - I have uploaded new pictures with more detail of the hinge area=
.. Take a look and let me know if you need more detailed pics. Also I have t=
he plans in a PDF that I can send you that came from Kay. Or, maybe I can u=
pload them here?

=A0
Hope I didn't leave out anybody comments or questions.=A0
=A0
Best,
=A0
Rich Schneider
KCMA - IRIS=A0


=A0
On Fri, Nov 25, 2011 at 9:10 PM, Dave Nelson <dave.nels=
on@...............> wrote:

Hi Brett

=A0Thats interes=
ting, as I though because most manmade local noise is vertically polarised,=
 the main one ... people walking around, then its going to be easier to pic=
k up on the vertical seismo.


well looks like I'm going to have to build one and see how it goes =
=A0:)

Richard, any chance of a pic with a bunch of measurements on i=
t please
so I can get an idea of some dimensions of the various bits and=
 close ups

of the hinge section
just email direct to me if possible

thanks l=
ots
Dave=20



At 08:50 AM 21/11/2011 -0500, you wrote:

Hi Dave,

I agree, Richard=
 has made a very nice looking instrument.

Regarding noise, I think i=
t's the other way around. =A0Generally the verticals are considerably l=
ess sensitive to local disturbances of the ground (though much more sensiti=
ve to temperature and barometric pressure changes). =A0Here's a couple =
of traces captured from the vertical channel (top trace) and one of the hor=
izontal channels of a Nanometrics Trillium Compact 120 three-axis instrumen=
t, operated by Dave Nelson in California. =A0 http://bnordgren.org=
/seismo/H_vs_V_-_Trillium_120.jpg

The wind was blowing that day and was shaking the ground quite a bit. =A0Th=
at's typical of what you would normally see.

Good verticals can =
be a lot harder to build, but they can perform much better in the sorts of =
locations that are likely to be available.


Although his instruments are located very close to the house =A0http://bno=
rdgren.org/seismo/IMG_1383s.jpg
Dave gets very good results w=
ith his verticals, whose traces =A0http://bnordgren.org/seismo/gif_ima=
ges.htm

can look as good or better than the USGS helicorder plots. =A0http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html


As we continue to test new designs, it appears that his vertical instru=
ments' sensitivity, as determined by their internal noise, may possibly=
 be a little better than his Trillium. =A0More testing in the works.

Regards,
Brett




__________________________________________________=
________

Public Seismic Network Mailing List (PSNLIST)

To lea=
ve this list email PSNLIST-REQUEST@.............. with the body of the message=
 (first line only): unsubscribe

See h=
ttp://www.seismicnet.com/maillist.html for more information.
=