Hi Brett,

I think you mean A/D not D/A, WinSDR does not deal with D/A converters. Also, I think
you mean X-Scale not Y-Scale. The Y-Scale controls the signal level (up/down motion)
in the real-time window or GIF image and the X-Scale controls the time. The number of
lines per channel and the time period per line has nothing to do with the Y-Scale. If
you mean the X-Scale, the X-Scale is in minutes per line.

Regards,
Larry Cochrane
Redwood City, PSN

Brett Nordgren wrote:
> Hi all,
> 
> I had recently been working with calculating the per-line scale factor for 
> some GIF's
> being produced by WinSDR, so I took the opportunity to try to characterize 
> how that
> generally relates to the number of lines displayed and the Y scale factor 
> setting.
> 
> So far what I have observed seems to suggest:
> 
> Given that
> n is the number of lines displayed
> Y is the WinSDR Y scale factor
> 
> For my screen (and possibly for any screen),
> D/A counts per line = 913 / (n+1) * Y
> So for a 24 hour - 24 line screen with Y = 2:
> counts per line = 913 / 25 * 2 = 73.04
> 
> If you are using a 16-bit, +-10V D/A you can go on to calculate:
> 
> Volts per line = 73.04 counts/line / 3276.8 counts/Volt = 0.0223
> 
> The constant 3276.8 is 32,768 counts / 10 V, the maximum values
> for a 16-bit +-10V D/A
> 
> And finally, from that, if you know your instrument's Volts / unit of 
> ground motion,
> you can divide by that number to get the ground motion represented by each 
> line.
> 
> This seems to hold true for both the screen displays as well as for GIF 
> file creation.
> 
> Larry, I'd be interested in whether this seems to make sense to you, and have
> I missed anything?
> 
> Regards,
> Brett
> 
> Watch our wiggles
> http://bnordgren.org/seismo/gif_images.htm
> 
> or watch some very very good wiggles
> http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html
> 
> 
> __________________________________________________________
> 
> Public Seismic Network Mailing List (PSN-L)
> 
> To leave this list email PSN-L-REQUEST@.............. with 
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
> 

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)