In a message dated 2008/07/27, christopher.marshall@....... writes:

> Then I found an old posting of yours about using the data window to set the 
> zero value, which worked! Turn out the zero value is 40,800, a value I never 
> would have found randomly. 

Hi Chris,

       First check the line voltages on Larry's amplifier, say on pins 7 and 
4 of the input opamp LT1007 with a DVM. They should be +/-12V.

       Then check the DC output voltage of your amplifier. If it is way off 
zero, adjust the voltage trim potentiometer on the amplifier.

       Then short the input to the ADC and check what reading you are 
getting. It is possible that there is a fault on Ch1, but if you have been using it 
OK with other programs, this seems unlikely.
 
The next issue is noise. I am using the lower gain channel on Larry's 
amplifier/filter 
> board and have Amaseis set on a gain of 1 with a decimate factor of 1. I am 
> getting electrical spikes at about a frequency of one Hz. Any ideas?

       Check your cables and the PSU. Unplug everything in sequence and see 
what effects this has. It is most likely an intermittent contact, but it could 
be a faulty PSU.

       Regards,

       Chris Chapman   
In a me=
ssage dated 2008/07/27, christopher.marshall@....... writes:



Then I found an old posting of=20=
yours about using the data window to set the zero value, which worked! Turn=20=
out the zero value is 40,800, a value I never would have found randomly. 



Hi Chris,



       First check the line voltages on Larry'=
s amplifier, say on pins 7 and 4 of the input opamp LT1007 with a DVM. They=20=
should be +/-12V.



       Then check the DC output voltage of you=
r amplifier. If it is way off zero, adjust the voltage trim potentiometer on=
 the amplifier.



       Then short the input to the ADC and che=
ck what reading you are getting. It is possible that there is a fault on Ch1=
, but if you have been using it OK with other programs, this seems unlikely.=


 

The next issue is noise. I am using the lower gain channel on Larry's amplif=
ier/filter 

board and have Amaseis set on=20=
a gain of 1 with a decimate factor of 1. I am getting electrical spikes at a=
bout a frequency of one Hz. Any ideas?




       Check your cables and the PSU. Unplug e=
verything in sequence and see what effects this has. It is most likely an in=
termittent contact, but it could be a faulty PSU.



       Regards,



       Chris Chapman