..Casey Crane wrote:

>> I've tried using a couple of the ADX line of accelerometers and was greatly
>> dissappointed, as the noise output of these was horrific.

In a message dated 06/08/01, dcrice@............ writes:

> Noise is relative.  If you had an earthquake strong enough to knock over 
> tall buildings in a single bound, these would probably be perfectly 
> adequate. They are not at all suitable for recording teleseisms and events 
> 

       I would sort of like to know about the quake just a bit before 
buildings start to collapse... 

       If Casey checks my EMail of 25/05/2001 he will see how to make a 
sensitive  sensor using a large piezo disk / sonalert. See also letter 
'piezo-geophone' on 02/07/01 by kd6iwd@.......... I can pick up a car over 
1/2 mile away on the main road with mine, on a still night. Forget the ADX / 
silicon chips; there is nothing else to touch a piezo under $10! You won't be 
disappointed.

       Regards,

       Chris Chapman
.Casey Crane wrote:



>> I've tried using a couple of the ADX line of accelerometers and was greatly

>> dissappointed, as the noise output of these was horrific.



In a message dated 06/08/01, dcrice@............ writes:



Noise 
is relative.  If you had an earthquake strong enough to knock over 

tall buildings in a single bound, these would probably be perfectly 

adequate. They are not at all suitable for recording teleseisms and events 

too small to waken a sleeping dog.



       I would sort of like to know about the quake just a bit before 

buildings start to collapse... 



       If Casey checks my EMail of 25/05/2001 he will see how to make a 

sensitive  sensor using a large piezo disk / sonalert. See also letter 

'piezo-geophone' on 02/07/01 by kd6iwd@.......... I can pick up a car over 

1/2 mile away on the main road with mine, on a still night. Forget the ADX / 

silicon chips; there is nothing else to touch a piezo under $10! You won't be 

disappointed.



       Regards,



       Chris Chapman