Greetings Jack,

            
When I visited the USGS.NEIC HQ in Golden, Colorado in 2006,

 John McMillan whas the lab tech that showed us lots of wonderful
gear

amongst that were the Gulrap Horiz and Vert  seismo's 

www.sydneystormcity.com/Guralp_CMG-V30_horiz_seismom1.JPG


www.sydneystormcity.com/Guralp_CMG-V30_vert_seismom1.JPG


maybe the same as you have acquired  :)    I dont
know if John is still there

but a phone call to there may get you some data sheets anyway


see how you go

Dave Nelson

Sydney




At 10:23 PM 5/2/2009 -0400, you wrote:

Folks,

I've come into possession of a late 80's vintage Guralp vertical force
feedback seismo.

Unfortunately, it has no model information.  It has a
3"x9" (waterproof-ish but not borehole-

ready) cylindrical sensor with very nice brass workings inside. 
There is also an amplifier

package in an aluminum cylinder.  It appears to use capacitive
position sensing, a force 

feedback coil, and a triangular leaf spring to give about a 2-Hz
mechanical period.  It 

has remote centering with a gearmotor, and a manual mass clamp for
shipping.  The

sensor has a cable coming out the bottom with a 10-pin MS connector on
the end, and

three pointed feet.  The sensor part looks pretty straightforward,
and I'm tracing the amp 

circuit (this will take a while).

This unit doesn't appear to be on Guralp's website.  



Anyone have any idea what I
have here?  I can take some pictures if it'll help. 
Anyone

gotten obsolete information out of Guralp before?

Thanks,

Jack