Re: [Discuss-gnuradio] Narrowband FM examples?

[Eric Blossom]

On Thu, Sep 18, 2003 at 03:47:10PM -0500, Paul J Zawada wrote:
> The narrow band fm example programs (nbfm.cc, nbfm4.cc) have been 
> commented out of the Makefile for a while now.  What exactly the issue 
> with that code?  Can they be used at all as-is?  If so, what's the 
> easiest way to generate a binary of one of those programs?  (I'm not up 
> to speed on autoconf/automake yet and I've had trouble coming up with a 
> working Makefile...)  I have both the CVS and tarball distributions...
> 
> Thanks
> 
> --zawada

They worked, last time I checked.  To be effective, they really need to
be used with some kind of FFT'ish front end that finds the center
frequency of the channel of interest.  The PLL in the 4937 has a 50KHz
step size, and not very tight specs on the reference, so trying to hit
something narrow band is a bit dicey.  If you know exactly where
you're signal is, you can of course tune it, by twisting the center freq
of the first down conversion in software.

To enable them, edit gnuradio/src/gnu/examples/Makefile.am, and add
them to the noinst_PROGRAMS list.  Also be sure to uncomment them out
down below.

Then, making sure you you've got all the right versions of the
autotools (see the README), from the top do:

          ./bootstrap
          ./configure --enable-maintainer-mode
          make

I realize this is a bit of a pain.  It's been biting me in the butt
for a while now too.  The plan, as soon as I get some breathing room,
is to add the support for pkg-config, which will support building
stuff outside of the gnuradio tree using very simple Makefiles.

Eric