Good evening - I am trying to make modifications to rtl_fm so that I can change frequencies, gains, modulation types, and squelch values on the fly (and thus avoiding a restart).  Its unclear to me what functions need to be called in order to apply changes to the sdr device so that I can do the above. The rtl_fm code isnt documented so I dont have much to go off of... GQRX doesnt run reliably on any RPi3's I've tried so I hoping to use a modified rtl_fm in its place. Any help would be appreciated. Thanks :)

At first I thought rtl_tcp was the way to go, but after looking at the code, it doesnt seem to support wide band FM, which led me to rtl_fm instead.  Also, when using rtl_tcp as a server, I found my signal strengths were weaker when connecting to the rtl_tcp server with GQRX.  I changed gqrx back to use the USB dongle directly and then i click the hardware agc checkbox - which gives me better signal strength.   Is that not typical behavior? Maybe I'm not configuring something correctly? Thanks :) On Mon, Jan 7, 2019, 18:16 <tom(a)tswartz.net wrote: Any reason that you couldn't use rtl_tcp instead? It's pretty common to run rtl_tcp on a remote RPi server, then use a different, local computer to host GQRX. Squelch, frequency changing, and other features should be available via that protocol presently. -- Tom Swartz On Mon, Jan 07, 2019 at 05:01:37PM -0500, Mark Russell wrote: (and code isnt a