In a message dated 2006/07/26, jpopelish@........ writes:

> And Chris, If you would like some drafting help making a more formal 
> drawing of this device, I can volunteer a bit of time.  But we should 
> do this off list, too, since it may take a bit of help from you, 
> before I get everything the way you want it.

       Thanks, I will try and get a part suppliers list out tomorrow and 
maybe some acutal drawings, rather than a freehand sketch. The devices seem to 
work quite well and mine goes down to ~4 sec - further than you can get with an 
uncompensated  geophone.

       For anyone who wants to extend the LF range of their geophones by x10, 
a circuit by P M Roberts is available. See 
http://www.seismicnet.com/bibliography.html

       Regards,

       Chris Chapman
In a me=
ssage dated 2006/07/26, jpopelish@........ writes:



And Chris, If you would like so=
me drafting help making a more formal 

drawing of this device, I can volunteer a bit of time.  But we should <=
BR>
do this off list, too, since it may take a bit of help from you, 

before I get everything the way you want it.




       Thanks, I will try and get a part suppl=
iers list out tomorrow and maybe some acutal drawings, rather than a=20=
freehand sketch. The devices seem to work quite well and mine goes down to ~=
4 sec - further than you can get with an uncompensated  geophone.



       For anyone who wants to extend the LF r=
ange of their geophones by x10, a circuit by P M Roberts is available. See h=
ttp://www.seismicnet.com/bibliography.html



       Regards,



       Chris Chapman