PSN-L Email List Message

Subject: RE: Stability of sound cards
From: "Keith Payea" kpayea@...........
Date: Tue, 11 Jul 2006 13:43:53 -0700


The easy way to think of it is that 100ppm is 100Hz(0.1KHz) at 1 MHz.
So, divide by 1000, and 100ppm is 0.1Hz at 1KHz.

	Keith 

-----Original Message-----
From: psn-l-request@.............. [mailto:psn-l-request@............... On
Behalf Of James Hannon
Sent: Tuesday, July 11, 2006 1:36 PM
To: psn-l@..............
Subject: Re: Stability of sound cards

I sure thought I counted my zeros right. If it is even better.

Jim Hannon

---------- Original Message ----------------------------------
From: "James L. Gundersen" 
Reply-To: psn-l@..............
Date:  Tue, 11 Jul 2006 12:27:59 -0700

>> Jim Hannon,
>
>Isn't +/-100ppm +/-0.01Hz at 1000Hz?
>
>Jim Gundersen
>
>----- Original Message ----- 
>From: "James Hannon" 
>To: 
>Sent: Tuesday, July 11, 2006 9:05 AM
>Subject: Stability of sound cards
>
>
>> Sound cards use a small surface mount crystal oscillator for their 
>> reference frequency. These oscillators typically have a stability of +/- 
>> 100 ppm over a temperature range of -10C to +70C. This is +/- 0.1 Hz at 
>> 1000Hz. Which is in the same ballpark as the 0.061 Hz per step at 12
bits. 
>> However the sound card is not very likely to see such temperature 
>> variations and there are ways of digitally removing offsets and slowly 
>> varying drift from the data.
>>
>>
>> Jim Hannon
>>
>> --
>> Jim Hannon
>> http://www.fmtcs.com/web/jmhannon/
>> 42,11.90N,91,39.26W
>> WB0TXL
>> --
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>
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>Public Seismic Network Mailing List (PSN-L)
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>To leave this list email PSN-L-REQUEST@.............. with 
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>

--
Jim Hannon
http://www.fmtcs.com/web/jmhannon/
42,11.90N,91,39.26W
WB0TXL
--
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