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peterw
2007-05-06, 13:45
I'd like to listen to local FM through my Squeezeboxes. Rather than settle for the rotten 32k streams some local broadcasters offer, I'd like to have an FM radio capture device on my Linux-based Slimserver host so that I could stream local radio at 320k MP3 (probably using OSS or ALSA to feed DarkIce so I could stream locally with Icecast, as I've done with my sound card line-in for my old stereo). I'd prefer a USB device both to get the tuner away from the in-case RFI, and to allow use with a small form factor PC like a Mac Mini.

Could anyone here who has used Linux USB FM radio capture devices offer some advice?

Thanks,

Peter

htrd
2007-05-07, 14:03
Ive been using a radioshark for offline recording.

http://www.griffintechnology.com/products/radioshark/

Software support in linux was tricky to get started. I needed to compile the small application used for setting frequencies, which needed a very new version of libhid from subversion. A quick google suggests this hasnt improved.

Once set up it has been largely problem-free. It provides an ordinary ALSA input device which I have been using to record scheduled broadcasts using arecord, scheduled by cron. All very tidy.

The only inconvenience is that the reception quality does seem to be quite sensitive to position. A couple of times it has been accidentally pushed against the wall at the back of the desk, and the reception really suffers. But maybe any other FM radio in the same position would have the same problem.

I am sampling at 48kHz and encoding as mp3, and audio quality is as good as I expect. Stereo FM broadcasts are band limited to 15kHz, and this ALSA input shows significant noise above that frequency. I noticed a worthwhile improvement in file size by configuring lame's lowpass filter at 15kHz.

I hope that helps.

peterw
2007-05-07, 20:38
Ive been using a radioshark for offline recording.
...
Once set up it has been largely problem-free. It provides an ordinary ALSA input device which I have been using to record scheduled broadcasts using arecord, scheduled by cron. All very tidy.

The only inconvenience is that the reception quality does seem to be quite sensitive to position.
...
I am sampling at 48kHz and encoding as mp3, and audio quality is as good as I expect. Stereo FM broadcasts are band limited to 15kHz, and this ALSA input shows significant noise above that frequency. I noticed a worthwhile improvement in file size by configuring lame's lowpass filter at 15kHz.

I hope that helps.

That helps a lot, thank you! The low pass filter sounds especially smart. I've ordered a new RadioShark off eBay (Amazon had a good deal last week, but the price has more than doubled in the last week) and am looking forward to giving it a try.

-Peter