Hi Jon,
                having iron in that area within the field of the magnet is=
=20
not a good idea
you would be much better off to use brass  if you didnt want to use=
 aluminium.

    I also notice from your photo's that your pickup wire from the coil
a rather heavy looking wire will also affect the movement of the arm.  The=
=20
usual
practice, if  a person insists of putting the coil on the arm, is to=20
terminate the
heavier wire at the pivot end of the arm and to use VERY FINE  from that=20
termination,  say 24-28 SWG enamelled wire wound in a loose coil say ~ 5=
 turns
  of pencil/ pen diameter, then terminate that fine wire on the base of the=
=20
seismom.
and then run heavier wire  again to the electronics.

I can almost guarantee that the way you have taken your wire off the arm=20
will have
a serious effect on the free movement of the arm!

Dave N
Sydney




At 07:32 PM 4/7/2009 +0000, you wrote:
>Hi
>I belive that I found the last problem (according to the idea). The last
>problem is the alunium rod that I have used as an arm. I belive that it
>was too soft to work properly and because of that I didn't behave
>correctly.
>I am going to replace it with iron based arm and there is going to be a
>steel based end on it. I hope that gives me the resault that I want.
>Regards.
>J=F3n Fr=EDmann.

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)