Hi Meredith
I have wanted to put a web site together like several of you folks =
have so nicely done but I seem to have a problem with documentation. I =
have made some photos but not to many yet. Written descriptions----well =
not yet. I can briefly describe what I have done wrt the SMT8 style =
verticals.=20
I think of the SMT8 in four parts.
1. the mechanical - boom, leaf spring, hinges.
On my first sensor I tried as closely as possible to duplicate the the =
SMT8 geometry. The only change I made was to remove part of the leaf =
spring support where it attaches to the end pins so I could slightly =
squeeze the ends of the bent leaf spring together and quickly remove it =
from the assembly w/o tools. On the second SMT8 I reproduced the first =
sensor but made the boom about 10 " long to try to make it more portable =
(for possible field use in an ammo box).
2. the displacement sensor
In the first sensor, I installed a homemade LVDT with phase shift =
oscillator and the demodulator that Karl Cunningham has described. In =
the second sensor I installed the VRDT hardware as STM described but =
with phase shift oscillator, instrumentation amp to sum and Karl's =
demodulator. Both work well and are quite linear. Side note: I calibrate =
the displacement sensors with a "diving board" type device that I =
calibrated with precision weights. I found it was easier to apply a =
precise weight than a small deflection directly. All the circuitry for =
either can be crammed on a 2X6.5 size breadboard. Not too complicated of =
circuitry, mostly just dual opamps. =20
3. the feedback circuitry =
=20
I used the Mathcad equations STM suggested.=20
4. mechanical adjustment control.
There are some adjustments I found necessary as STM had described in =
depth. The vertical is not as sensitive to tilting but is sensitive to =
temperature and the initial relaxation of the leaf spring. For =
temperature correction I installed a bimetal thermometer coil near the =
boom. With some trial and error positioning and thermal insulation I was =
able to remove a substantial amount of this temperature variation. For =
zero adjustment I used the Edmond Scientific low rpm motor and threaded =
rod and sliding weight. Works well. =
=
=
=20
I made most of the mechanical parts with small handtools. I have a small =
drill press, files, tap set, vise, 1" micromometer and access to a =
surplus store with aluminum. For the electronics I do have a DVM, =
soldering iron and an inexpensive oscilloscope which I found valuable =
for several things. I have wanted to use pc boards that I etch but =
haven't found the time yet to learn and perfect. I initially use 2' X =
6.5" solderless breadboards. to position and check the circuitry. When I =
am happy I move them to the pre-etched boards that RS sells that are =
the same size and layout. =20
Though I'm still trying to improve things (as we all are) if I can help =
any further let me know.
Regards
Barry
=20
----- Original Message -----=20
From: meredithlamb=20
To: psn-l@.................
Sent: Wednesday, November 13, 2002 12:28 PM
Subject: Re: STM 8 (previous Sprengnether subject email)
Hi Barry and all,=20
Glad your STM 8 is still working. Sean-Thomas=20
Morrisseys vertical seismo created alot of interest ~ afew=20
years ago of course. I think it also had alot of confusion=20
along the line of the exact electronics components used and=20
its adjustments involved for various reasons.....their was a=20
long line of emails with corrections thereafter that kind of=20
left me and perhaps others in the lurch so too speak. It just=20
might be that you are the only "knowledgeable person " left=20
that perhaps has some more exact circuitry/operation/setup=20
info than anyone else. It was a rather involved circuitry I=20
think. You may even have changed components that would=20
be of interest also. Its perhaps prudent to say that these=20
corrected documents (however assembled) are invaluable to=20
those wishing to try a duplication. I've little electronics=20
background myself, and I'd guess most individuals are in the=20
same rough class.=20
I think St. Louis University "was" thinking of trying to get a=20
U.S. Patent; but as of recent date, I've seen nothing suggesting=20
such (it could be in the "pipeline", so too speak of course). On=20
the other hand, it may have been set aside for other financial=20
reasons; or even abandoned. Its also possible that the STM=20
website display with the mechanics and circuitry itself prior to=20
any Patent application could have placed the entire unit in a=20
"public domain" category which in itself prevents any Patent=20
granting success. I just don't know. Regardless, its "still"=20
likely the best broadband vertical design around for its=20
cheapest home building approach.....which I'am sure Sean=20
was encouraging.=20
There was a number of individuals trying to duplicate the unit,=20
but, I've no idea of their success. As I recall, one or two=20
were considering other sensor/amplifier methods outside of=20
the original design, but I've no idea of how that went.=20
http://www.eas.slu.edu/People/STMorrissey/index.html=20
Take care, Meredith Lamb=20
=20
Hi Meredith
I have =
wanted to put=20
a web site together like several of you folks have so nicely done but I =
seem to=20
have a problem with documentation. I have made some photos but not =
to many=20
yet. Written descriptions----well not yet. I can briefly describe =
what I=20
have done wrt the SMT8 style verticals.
I think of=20
the SMT8 in four parts.
&nbs=
p; =20
1. the mechanical - boom, leaf spring, hinges.
On my first sensor I tried as closely =
as possible=20
to duplicate the the SMT8 geometry. The only change I made was to remove =
part of=20
the leaf spring support where it=20
attaches to the end pins so I could slightly squeeze =
the=20
ends of the bent leaf spring together and quickly remove it from =
the=20
assembly w/o tools. On the second SMT8 I reproduced the first =
sensor but=20
made the boom about 10 " long to try to make it more portable (for =
possible=20
field use in an ammo box).
&nbs=
p; =20
2. the displacement sensor
In the first sensor, I =
installed a=20
homemade LVDT with phase shift oscillator and the demodulator that Karl=20
Cunningham has described. In the second sensor I installed =
the VRDT=20
hardware as STM described but with phase shift oscillator, =
instrumentation=20
amp to sum and Karl's demodulator. Both work well and are quite linear. =
Side=20
note: I calibrate the displacement sensors with a "diving board" type =
device=20
that I calibrated with precision weights. I found it =
was easier=20
to apply a precise weight than a small deflection directly. All the =
circuitry for either can be crammed on a 2X6.5 size breadboard. Not too=20
complicated of circuitry, mostly just dual opamps. =20
=20
3. the feedback=20
circuitry &nbs=
p; =
; =
&=
nbsp; &n=
bsp; &nb=
sp; &nbs=
p; =20
I used the Mathcad equations STM =
suggested.=20
&nbs=
p; =20
4. mechanical adjustment control.
There are some adjustments I found =
necessary as STM=20
had described in depth. The vertical is not as sensitive to =
tilting=20
but is sensitive to temperature and the initial relaxation of the leaf =
spring.=20
For temperature correction I installed a bimetal thermometer coil near =
the boom.=20
With some trial and error positioning and thermal insulation I was =
able to=20
remove a substantial amount of this temperature =
variation. For zero=20
adjustment I used the Edmond Scientific low rpm motor and threaded =
rod and=20
sliding weight.=20
Works well. &nb=
sp; &nbs=
p; =
; =
&=
nbsp; &n=
bsp; &nb=
sp; &nbs=
p; =
; =
&=
nbsp; &n=
bsp; &nb=
sp; &nbs=
p; =
; =
&=
nbsp; &n=
bsp; =20
I made most of the mechanical parts =
with small=20
handtools. I have a small drill press, files, tap set, vise, 1"=20
micromometer and access to a surplus store with=20
aluminum. For the electronics I do have a DVM, soldering =
iron and an=20
inexpensive oscilloscope which I found valuable for several=20
things. I have wanted to use pc boards that I etch but =
haven't=20
found the time yet to learn and perfect. I initially use 2' X 6.5" =
solderless=20
breadboards. to position and check the circuitry. When I am happy I move =
them to=20
the pre-etched boards that RS sells that are the same size and=20
layout.
Though I'm still trying to improve =
things (as we=20
all are) if I can help any further let me know.
Regards
Barry
----- Original Message -----
From:=20
meredithlamb
Sent: Wednesday, November 13, =
2002 12:28=20
PM
Subject: Re: STM 8 (previous =
Sprengnether=20
subject email)
Hi Barry and all,=20
Glad your STM 8 is still working. Sean-Thomas
Morrisseys =
vertical=20
seismo created alot of interest ~ afew
years ago of course. =
I think=20
it also had alot of confusion
along the line of the exact =
electronics=20
components used and
its adjustments involved for various =
reasons.....their=20
was a
long line of emails with corrections thereafter that kind of =
left me and perhaps others in the lurch so too speak. It =
just=20
might be that you are the only "knowledgeable person " left =
that=20
perhaps has some more exact circuitry/operation/setup
info than =
anyone=20
else. It was a rather involved circuitry I
think. You =
may even=20
have changed components that would
be of interest also. Its =
perhaps=20
prudent to say that these
corrected documents (however assembled) =
are=20
invaluable to
those wishing to try a duplication. I've =
little=20
electronics
background myself, and I'd guess most individuals are =
in the=20
same rough class.=20
I think St. Louis University "was" thinking of trying to get a =
U.S.=20
Patent; but as of recent date, I've seen nothing suggesting
such =
(it could=20
be in the "pipeline", so too speak of course). On
the other =
hand, it=20
may have been set aside for other financial
reasons; or even=20
abandoned. Its also possible that the STM
website display =
with the=20
mechanics and circuitry itself prior to
any Patent application =
could have=20
placed the entire unit in a
"public domain" category which in =
itself=20
prevents any Patent
granting success. I just don't =
know. =20
Regardless, its "still"
likely the best broadband vertical design =
around=20
for its
cheapest home building approach.....which I'am sure Sean =
was=20
encouraging.=20
There was a number of individuals trying to duplicate the unit, =
but,=20
I've no idea of their success. As I recall, one or two
were=20
considering other sensor/amplifier methods outside of
the original =
design,=20
but I've no idea of how that went.=20
http:=
//www.eas.slu.edu/People/STMorrissey/index.html=20
Take care, Meredith Lamb