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Matt D md123 at nycap.rr.com-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 03/31/2013 07:22 PM, souf308 wrote: > OK I think I actually found out how to use the info file. But I > still need some help to configure the parameters in the OP25.grc > and use the samples (sorry to bother you with those beginners > questions) ---------------------------- Here is the info file (from > the website) (dp0 S'capture-rate' p1 I250000 sS'source-decim' p2 > I256 sS'source-dev' p3 S'USRP' p4 sS'center-freq' p5 F434075000.0 > s. --------------- So * 'capture-rate' corresponds to the parameter > 'samp_rate' in grc file hence samp_rate=250000 > > * 'center frequency'=434075000.0 > > *but what about 'channel_rate'? (=250000?) > > *In this formula (channel_rate/(2.0 * math.pi * > op25.SYMBOL_DEVIATION)) what is op25.SYMBOL_DEVIATION??? > > *what is samp_per_sym?? > > Thanks in advance for you help > > Souf > Hi Souf, yes the capture rate is the sample rate. sample per symbol is what changes the channel rate, don't change the channel rate directly; I believe the channel rate should be between 19.2k and 43.2k. decimation changes the pre_channel rate, looks like he had it set at 256. I have found that it is best to play a file is with the flow graph set exactly as it was set when the file is captured. If you want to have a go with a capture I made I put the file up for download at: http://www.fileswap.com/dl/9kfgeOXMz/ I think the frequency, sample rate, decimation, and symbol_per_sample information is in the tar file. put a throttle right after the file source or the file will play in about 11 seconds instead of the real speed of about 40 seconds. so when you play the file first you tune to the frequency, next on the BB-1 tab you wait for the carrier freq to pop up, then go to the X-late1 tab and use the offset to get the channel at zero and narrow the bandwidth with the xlateBW slider, then go to the Dbits tab select autorange and change the marker to dots. you'll see the dots go from scattered into 4 perfect lines and you'll hear the transmission. Thanks -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iQEcBAEBAgAGBQJRWPJfAAoJEIC13XTKWhPPeosH/R3j/UL1rWBB7iOxkkjLjj2U 74nLrPdRaeVZ7RbTQzZTiSp+b1FGgMxB9JUafimlsts7ILusGo+OZGvsAWGGuUmQ sjNih8+ZR1kaSnZ8EKWeYOrd5TdobIZ7rhP5cO5VzToHBp0EG/LItIfoCOKuIxsA do2z/MBsbqx0jFObu+F4yFEnbp5tZthP2cjibWH6+6hQC4lj6VVrvbNWm4Pv74ku KrLMOSu6rk7rB0KVcJBYh1UO+owUt8AItX52TU9LxVl4h+Zb2L1BwC0rBMvHaf0I GrHlRwVxMYYB2NWiRgNPLbOy4XChpbpTgdbi9VaBmJoqC4jX6nk60Clz5OagRm4= =x92D -----END PGP SIGNATURE----- -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.osmocom.org/pipermail/op25-dev/attachments/20130331/00c576e2/attachment.htm>