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    Scott Young

    KBPS has been broadcasting in stereo for several years but almost no one knows what AM stereo sounds like these days. With that in mind I set up a little stream to demo KBPS in stereo. It’s a 256 mp3 stream fed from the new Delta modulation monitor. Using an Omnia for processing right now but we have a new Optimod we hope to have in service fairly soon. You can hear the stream here:

    All the music in the classic pop/rock library is from lossless sources and none of it is “brickwalled.” A good portion of the library has been “unbricked” but one way or another all of it has nice dynamics. Before we “brickwall” it for air that is…


    Thank you for re-posting that item. Great audio!

    Scott Young

    Thanks Chessyduck! The audio on this little stream is a lot better from the mod monitor than it was from the Carver tuner. Still an over the air signal to the stream though, since the mod monitor is a tuner set to 1450.


    I listened to the stream for a while this afternoon. Nice clean stereo separation and wide frequency response. Something may be over-boosting the high frequencies though, kind of shrill. I offer that as a constructive listener observation, not a criticism. The fact that C-QUAM is still alive in any form is very cool.

    They (FCC) could have been more aggressive about saving AM! But no.

    Scott Young

    I hear that too last day. It sounds like a bump in the upper mids like you’d do for narrowband AM radios.


    I heard “True” which always sounds great on FM but no so much here.


    I swear that when I hear “True” played almost anywhere, I can hear the razor blade edits. According to Wikipedia, four versions of this song were released.

    Scott Young

    KBPS has been playing the 5:30 single edit of “True” but the 6:30 LP version is pretty nice and prompted by the comments in this thread I switched to the LP version. KBPS plays mostly LP versions unless there’s a compelling reason to do otherwise, but the version differences on “True” escaped me until now. Thank you Alfredo! According to Pat Downey’s online database there are three versions out on domestic CDs…the 5:30 single edit, the 6:30 LP version, and a 5:40 edit of the LP version.

    The source file for the single edit we play sounds just fine. Not sure why it wouldn’t make it through the processing and on the air as well as anything else in the library.

    • This reply was modified 1 month, 2 weeks ago by Scott Young.

    Interesting hearing mediumwave stereo today. The last time I remember hearing it was on “AM Only” via 1520, in my Grandmother’s ’96 Chrysler LHS with factory radio. That had to have been 20 years ago at least.

    1520 really sounded fantastic for what it was and I think they must have been using AMAX processing. I nearly flew out of my seatbelt first time I heard it in stereo, as a teenager! Usually she had the audio on the front speakers (because, more often than not, I would have a tape or (later) disc running on my headphones) but that day she didn’t.

    I haven’t had access to a CQAM rig in about that long. Grandmum sold the car in 2006, and with it the stock radio.

    Scott Young

    AM Stereo does sound surprisingly good. It’s a shame it didn’t have staying power. I think it makes a lot more sense on AM than IBOC does. In the same way I’d rather hear vinyl artifacts in music than low bitrate mp3 artifacts, I’d much rather hear impulse noise in well engineered CQUAM than low bitrate IBOC artifacts. Not to mention the fact that AM broadcasters will never finish paying for their Ibiquity noise makers!


    I am lucky enough to still have a portable Sony radio, designed for the Japanese market, that receives CQUAM signals. Back in February of this year, when we had the ice storm, I lost power for about 4 days. One of the benefits of that was being able to listen to KBPS, in stereo, without the usual interference I usually get on 1450 in this area. The interference doesn’t make the station completely unlistenable, but it isn’t quite as enjoyable as it was for those 4 days when I got a beautiful clear CQUAM signal. By the way, the batteries in that radio lasted through the entire time, and it was on a good portion of that time. Anyway, the point is, when you have a nice clear signal, CQUAM can sound really good. Now, I just have to keep searching to figure out what electrical appliances are contributing to the usual interference that plagues my AM radios. Well, we’ll save that for another time.

    • This reply was modified 1 month, 2 weeks ago by Clinton. Reason: Had to fix a typo

    Now, I just have to keep searching to figure out what electrical appliances are contributing to the usual interference that plagues my AM radios. Well, we’ll save that for another time.

    Widescreen television
    ATSC/QAM//DVB/DSS receiver
    DVD-video player
    Computer equipment
    Stereo system
    Laptop wall wart
    Cell-phone wall wart
    802-11 router/transceiver
    xyzDSL transceiver
    DOCSIS equipment
    LED/compact fluorescent
    Battery charger
    Fiber-to-the-node gateway (if you have that)

    The list could go on and on and on and on. Basically you can and should consider anything containing a switching power supply and made within the last ~20 years suspect.

    Plasma widescreens, especially around the turn of the century were noiser than fuck, sometimes even more so than CRTs. LED lights, particularly poorly-filtered Chinese units, aren’t exactly the quietest things around, either.




    Been a while since I posted this so…
    Was about 10 miles out heading to Vancouver. Found KBPS in AM Stereo on the Ford Motorola radio. Sounded good. Someone hadn’t informed the student DJ about KBPS being in stereo. He was lamenting about being in mono AM.

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