Dear Dave Saum,

       The data sheets for the EV-17 vertical can still be found at 
http://www.bc.edu/bc_org/avp/cas/wesobs/seismometers/ev17.pdf

       The 'standard' coil resistances are 500 and 5000 Ohm. The 0.7 critical 
damping resistors are 1,300 or 13,000 Ohm. The wiring connections are not 
given, but the sheet claims 'Use of a standard ETL P14A plug-in connector 
facilitates quick cable and damping resistor changes when desired'. The photo 
shows a single connector with a Y jointed lead, suggesting that at least two 
connections are required. 

       Are they in insulated pairs? One pair may be a calibration coil. Could 
the other one be a temperature sensor? What are the resistances? Does the 
output of the 5 K coil change when you put say 1 mA through another pair? 
Give the case a tap and see if the 5 K output is damped and if the other 
connectors give any signal at all.

       Regards,

       Chris Chapman
Dear Dave Saum,



       The data sheets for the EV-17 vertical can still be found at http://www.bc.edu/bc_org/
avp/cas/wesobs/seismometers/ev17.pdf



       The 'standard' coil resistances are 500 and 5000 Ohm. The 0.7 critical damping resisto
rs are 1,300 or 13,000 Ohm. The wiring connections are not given, but the sheet claims 'Use of a standard ETL P14A plug-in conn
ector facilitates quick cable and damping resistor changes when desired'. The photo shows a single connector with a Y jointed l
ead, suggesting that at least two connections are required. 



       Are they in insulated pairs? One pair may be a calibration coil. Could the other one b
e a temperature sensor? What are the resistances? Does the output of the 5 K coil change when you put say 1 mA through another 
pair? Give the case a tap and see if the 5 K output is damped and if the other connectors give any signal at all.



       Regards,



       Chris Chapman