[aprssig] Help needed: APRS receive with RTL_SDR and Direwolf
John Langner WB2OSZ
wb2osz at comcast.net
Wed Aug 14 21:17:46 EDT 2019
I see several issues here.
> Dire Wolf version 1.0a
That version is more than 5 years old. There have been a lot of
improvements and bug fixes since then, I would recommend getting the latest
stable version.
> $ rtl_fm -f 144.39M -M nbfm -E offset 0 -g 11 -p 60 -r 24000 - |
-M should not be necessary because it defaults to narrow fm. "nbfm" is
not listed as a choice in the documentation.
http://kmkeen.com/rtl-demod-guide/ "fm" means narrow FM.
-g is setting the gain very low. " Tuner gain set to 12.50 dB." Remove
it.
-p is to compensate for cheap devices being way off frequency. " Tuner
error set to 60 ppm." Remove it and experiment later if necessary.
-E offset I don't understand what this is doing. Remove it.
> direwolf -c direwolf.sdr.conf -r 24000 -p -D 1 -
Don't use -p option unless you understand what it means and really need it.
This would cause earlier versions to hang when used unnecessarily.
Did you read this?
https://github.com/wb2osz/direwolf/blob/master/doc/Raspberry-Pi-SDR-IGate.pd
f
73,
John WB2OSZ
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