Hi Dave=0AMy little seismometer has about 2 ounces of lead. =0A=0A=0AI use =
a resistor across the coil as the damper. Put a 1k ohm pot across the coil =
and then check for the damping factor per Chris Chapman's recent post. Adju=
st the pot until you have critical damping and you are done.=0A=0A73,=0APet=
e=0A=0A=0A=0A________________________________=0AFrom: Dave Nelson =0ATo: psnlist@...................... Monday, July 25, =
2011 2:41 PM=0ASubject: RE: New Seismo=0A=0A=0AHi Randy,=0A=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0=A0=0Aahhh now there's some words of wisdom that I =
hadnt thought about =0Abefore. hmmm but the balance point would be probably=
 right at the=0Aweights.=0AThe other seismo's I have seen online=A0 Chris C=
's one that I have=0Asorta copied,=0Athe SEP, and others, the support wires=
 have been some distance back from=0Athe =0Aweights.=A0=A0 Out of curiosity=
 how much weight do you have on your=0Aone ?=0Awhat are other guys using ?=
=A0=A0 Gosh I was thinking 4 pounds was=0Anowhere near =0Aenough and would =
have preferred almost twice that amount.=A0 Thats=0Aconsidering the=0A=A0Sp=
rengnether I had in NZ had ~28 lbs os mass.=0A=0AAll that being said I coul=
d still take the support wires to the other end=0Aof the frame =0Aholding t=
he coil magnets and gain a bit more ib the balancing act=A0=0A:)=0A=0Aspeak=
 up all=A0=A0 what weights are commonly being used ? and how=0Amany of you=
=0Aconsidered the balance point of the boom when adding the support wires=
=0A?=0A=0Acheers=0ADave=0A=0A=0AAt 12:17 AM 26/07/2011, you wrote:=0A=0AHi=
=0ADave,=0A>If you remove the boom and find the balance point of the boom y=
ou can=0Are-attach the support wire at or very near that point.=A0 This wil=
l=0Aremove the vertical force on the pivot and allow it to sit in=0Aplace.=
=A0 Another option would be to remove one weight.=A0 Removing=0Athe weight =
would also help to increase the damping effect.=A0 With 4=0Apounds of weigh=
t in my experience you will not get enough damping with=0Athe 1 small magne=
Hi Dave
My little seismometer has about 2 ounces of lead. 
=

I use a resistor across=
 the coil as the damper. Put a 1k ohm pot across the coil and then check fo=
r the damping factor per Chris Chapman's recent post. Adjust the pot until =
you have critical damping and you are done.

73,
Pete

From: Dave Nelson <dave.ne=
lson@...............>
To:
 psnlist@..............
Sent: Monday, July 25, 2011 2:41 PM
Subject: RE: New Seismo

=0AHi Randy,
=0A         =
;     =0Aahhh now there's some words of wisdom tha=
t I hadnt thought about 
=0Abefore. hmmm but the balance point would be =
probably right at the=0Aweights.
=0AThe other seismo's I have seen onlin=
e  Chris C's one that I have=0Asorta copied,
=0Athe SEP, and others=
, the support wires have been some distance back from=0Athe 
=0Aweights.=
   Out of curiosity how much weight do you have on your=0Aone ?=0Awhat are other guys using ?   Gosh I was thinking 4 pounds w=
as=0Anowhere near 
=0Aenough and would have preferred almost twice that =
amount.  Thats=0Aconsidering the
=0A Sprengnether I had in NZ =
had ~28 lbs os mass.

=0AAll that being said I could still take the s=
upport wires to the other end=0Aof the frame 
=0Aholding the coil magnet=
s and gain a bit more ib the balancing act =0A:)

=0Aspeak up al=
l   what weights are commonly being used ? and how=0Amany of you<=
br>=0Aconsidered the balance point of the boom when adding the support wire=
s=0A?

=0Acheers
=0ADave

=0A
=0AAt 12:17 AM 26/07/2011, =
you wrote:
=0A
Hi=0ADave,
=0AIf you remove the bo=
om and find the balance point of the boom you can=0Are-attach the support w=
ire at or very near that point.  This will=0Aremove the vertical force=
 on the pivot and allow it to sit in=0Aplace.  Another option would be=
 to remove one weight.  Removing=0Athe weight would also help to incre=
ase the damping effect.  With 4=0Apounds of weight in my experience yo=
u will not get enough damping with=0Athe 1 small magnet.  
=0ARandall L.=0APratt

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