Hello PSN;

It is my experience you will need
at least 12 bits resolution for satisfactory results
else you need very high gain like for
8 bits min number of bits.

16 bits is very good at +/- 5 volts
and with 24 bits at +/-5 you might
need little or no gain at all.

The overall gain at 1 Hz seems to be about
80Db counting everything.
80Dbv being X10,000 AC volts at 1 Hz.
Using a sensor with about 3V/Inch/Second.

This means no matter how many bits
the output full scale at 1Hz
will occur with the same input
but the overall amplifier gain will
be marked less as you increase the
bits from 8 to 24.
But the overall gain is still X10,000
from input to output 1Hz AC if the sensor
is 3V/Inch/Second velocity type.

I will not tell you of a design which I know
works well since I'm not an Engineer.

But I do know the preamp and equalizer
should be the same device to avoid jamming at high
frequencies by manmade ground noises.
All necessary filtering to happen before the
final output amplifier. A Dc blocker is desired
prior to isolation manifold buffer amplifiers
for like the Meters and A/D.

It is cheaper and easier to buy everything
already built than to experiment with
building your own. Unless you can get
your hands on a non-copyrighted design.
Or design your own and not share it
for fear of the Law.
You are not allowed to distribute a design
which is actively copyrighted or so I think.

Most circuits published by chip manufacturers
are public domain and I see no reason
you can not use those patched together
to build whatever as your own private kit
For your own private use.

Warning to the ignorant: (just ignore this if you dare)
The USA is a very nasty place when it comes to law.
You must be more careful here than in some other countries.
Or so it seems.
Must not gain money from actively patented designs.
If they are patented you must get them from their
patent holder one way or another.
Some people think the USA is a free country.
Only the ignorant and simple minded believe this way.
I see more freedoms in other countries in the case
of victimless crime which in my mind is no crime at all.

When Lawyers charge $500 for the tiniest
of services, I have to say, they are themselves,
are Organized crime. They are richer than they
deserve to be. They, like Psychologist, Financially Prey on
helpless hurting individuals.

Avoid them unless you are going into business,
then its better to study the law yourself.

I'm talking here not about the criminal law
but the civil law. They are two isolated topics
in the USA. In my mind the civil stuff should
not be allowed. They are to me like vigilantes.
Hypothetically, civil law has no teeth or claws.
But if the people employing the civil laws are
criminal themselves, you as an individual will
not be able to defend yourself from them.
You must keep these ideas in mind
if going public with potential money making ideas.
Lots of folks trying to make too quick bucks.
The legal branch is underfunded.
They stoop to questionable means to make up for this fact.
My life / liberty has been illegally destroyed by such nasty peoples.
So be careful. I am living in a jail where the neighbors are criminal
and the invisible bars exist according to economics.
I have no idea why they were too cowardly to simply shoot/kill me.
They must have religion or some social insect Philosophy unknown to myself.
They are Caucasian/Nationwide/Insidiously, Chronically, Murderously Criminal.
The FBI has no interest in pursuing them.
They hide under skirts of Medical And The Law.
They do not pick on Government, Only helpless individuals, whom Government is not interested.
It is a Federal Jurisdictional Thing with no Justice waiting.
I think we citizens need a new civil war to win back our constitutional rights.
Rights which have been lost before I was born.
Rights are for the individual person, not the organized groups.
To protect the helpless individual from the oafish/powerful/unreasonable group.
I can not place a name on this nationwide nasty group of seemingly Christian Caucasians.
I can only say they are deadly Chimp like things with PhDs and Follower Soldiers to get on your back.
I'm not joking here, unless you have a nuclear army at your personal command, be careful, you cant fight them
Only curl up and die. They are ONLY afraid of mass destruction. When in their groups, they are not human.
I really think the very same people killing me were the ones who killed Kennedy.
If you are powerless they take their sweet time.
If you are powerful, and these tactics will not work, then they kill you outright.
John,Robert, MLK were all victims of this same culture.
No telling how many others.
I am unable to put a name on them. Possibly, Just a guess, Christian Protestant Academy/University Graduates.
They are also the Phantom Government waiting to take over in a national emergency. Consisting of Many Academic disciplines.
Smart, Cold Hearted, Tenacious, Organized, Ruthless, Unlike Anything seen before in human history. Maybe even participating within 
PSN.
They are everywhere the public is. You can't do anything meaningful outside their access.
It is suicidal to fight them as an individual.

GutLuk Comrade
geoff


-----Original Message----- 
From: Richard Schneider
Sent: Sunday, November 21, 2010 8:32 PM
To: PSNLIST@..............
Subject: My AS-1 Type Sensor


Hello, I'm new here and have a few questions.

I recently constructed an AS-1 type sensor. My station KCMA is on the IRIS network.

http://www.iris.edu/amaseis/schools/as1imgs/KCMA.png

I am using an amplifier/filter, designed by Andy Loomis, which works quite well. The natural period of the sensor is 1.7 seconds. 
The cutoff period of the filter is set at 1.4 seconds.

My questions are.... Does anyone have a amplifier/filter design that will extend it to 10 to 15 seconds? I know the manufacturer of 
the AS-1 can provide the amp/filter, but it's a bit too pricey for my budget. And, I believe somewhere, on the psnlist, I recall 
someone who had made improvement's to the AS-1 amp/filter. Any recommendation's?

Additionally, my ADC is a Dataq 194RS which is only a 10 bit unit. The original AS-1 "black box" operates at 12 bits. Is 10 bits 
satisfactory or do I need a higher range?

Lastly, if anyone has an AS-1 "black box" for sale, I would be interested.

Thank you,

Richard Schneider 

__________________________________________________________

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.html for more information.