FM broadcast SCA audio from SDR software?

[ThaDood]

Ya know... I've been reminded of a kit that ya add to the IF of an FM broadcast RX to decode the SCA audio. I've thought for years of doing this, but in our ever encroaching digital age, I'm wondering if any major FM stations from major metro areas are doing it anymore. But, if any still are, can SDR software decode that? Am I wayyyyyyyyyyyyyy to late to even ask this?

[redhat]

...I'm wondering if any major FM stations from major metro areas are doing it anymore.

https://youtu.be/fdCkFrde4jQ

When I started in broadcast engineering, some of the local public stations did "books for the blind" using SCA equipment installed at the transmitter sites.

+-RH

[ThaDood]

Ya know, with SCA MPX'ing around for decades, how come no one seemed to have the foresight to have those MPX'ed channels to broadcast various news, talk, NOAA WX, other MX formats, or even paid programming, to the SCA service, but to only have an incredibly myopic use of this service? The idea of extra channels, as with HD Radio today, could have been way more utilized years ago.   

[redhat]

Primarily because receivers were not widely available and adding subcarriers does cause degradation to the host stations program audio, as well as loudness loss.  SCA injection needed to run around 20%, and this meant the host stations program audio would have to be reduced by that amount to keep the peaks under 100%.  The commission later added an exception stating that for every percent of subcarrier injection, the peak modulation could be increased by 0.5%.  This means if you are running 20% injection of SCA (or RDS interestingly) your new peak ceiling is 110%.

+-RH

[ChrisSmolinski]

I used to have several local FM stations transmitting SCA, but it had been several years since I checked, so I just did. I did not find any, except for 107.7 which is transmitting an unmodulated SCA carrier at 67 kHz.

[RobRich]

AFAIK, there were some dedicated SCA broadcasters in South Florida years ago. Seems I remember Metrosonix being mentioned for modified portables.

http://www.metrosonix.com/

Looks like Metrosonix still offers some models. Around $40 to $90 from a quick skim of stock. o.0