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<DIV>Hey Alex,</DIV>
<DIV>If you mean that you are saving to disk the raw ADC samples, then the files
will be the same size, regardless of how many or how few signals are
there. No signals just means a lower value will be recorded to the
disk. But probably very few 0x0000 values. More stations just means
more recorded samples with higher values. The file size will depend only
on number of bits per sample, the sample rate, and the length that samples are
recorded.</DIV>
<DIV> </DIV>
<DIV>Same with noise versus no noise. This all assumes NO fancy
compression techniques are used on the file. No noise means sample values
will be closer to zero, noise means more randomness of, and higher values in the
samples.</DIV>
<DIV>73, Terry, N4TLF</DIV>
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<DIV style="font-color: black"><B>From:</B> <A title=beatnic@comcast.net>Alex
Fraser</A> </DIV>
<DIV><B>Sent:</B> Tuesday, May 30, 2017 12:54 PM</DIV>
<DIV><B>To:</B> <A title=tacos@amrad.org>AMRAD Tacos</A> </DIV>
<DIV><B>Subject:</B> Re: Three new SDRs in the shack</DIV></DIV></DIV>
<DIV> </DIV></DIV>
<DIV
style='FONT-SIZE: small; TEXT-DECORATION: none; FONT-FAMILY: "Calibri"; FONT-WEIGHT: normal; COLOR: #000000; FONT-STYLE: normal; DISPLAY: inline'><FONT
size=+1 face="Comic Sans MS"></FONT><FONT size=+1 face="Comic Sans MS">I was
thinking this morn, probably the coffee. <BR>So if you record to disk I
would think that if you captured a portion of the spectrum with many stations
that the file size would be greater than a less busy part of the
spectrum. Is that true? Then I thought if you recorded a part of the
spectrum with noise at a certain level and then recorded another part of the
spectrum with a higher noise level, then would the 2 files sizes be the same or
different? I'm ignoring OS overhead.<BR>I'm sure there is a mathematical
explanation for this and if need be I WILL drink more coffee...<BR><BR>Terry Fox
wrote on 5/29/2017 8:46 PM:
<BLOCKQUOTE type="cite">I have recently purchased three new SDRs for testing
and playing with. Up front: I have NO RELATIONSHIP with any of
these companies, other than being a customer, who paid full-price for
everything. <BR><BR>1/2: BooyaSDR <BR>The first two are BooyaSDR
units. These are different than almost all other SDRs available to RF
enthusiasts at the moment, in that they sample the RF input directly, then
send ALL those samples to the host computer. No FPGA or other device to
reduce the amount of samples. The host computer then does all the
computations to show the FULL bandwidth of their respective input. The
software shows this spectrum display in a series of waterfalls stacked on top
of each other. I purchased one of the 100MHz full SDR & antenna, and
then a 16MHz digitizer set, less antenna. I also have a 64MHz oscillator
that I can put in place of the socketed 100MHz oscillator, so I can test the
boards at that lower rate.
<BR><BR></BLOCKQUOTE>----------------------snip--------------</FONT><FONT
size=+1 face="Comic Sans MS"> </FONT><PRE class=moz-signature cols="72"><FONT size=+1 face="Comic Sans MS">--
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No electrons were harmed in the creation of this message
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~~~******************* Alex Fraser *******************~~~
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[[[[[[~~^^^#___=>>>```/\/\**O**/\/\```<<<=___#^^^~~]]]]]]
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