He Loves That AM Stereo Light


Jake Bechtold, CBT, posted this image on his Twitter feed with the comment, “The AM stereo light has been turned back on on 1660. Thank you HD3 simulcast!”

He is assistant engineer/IT for Radio FM Media, based in Fargo, N.D., and the station that turned AM stereo back on is KQWB West Fargo.

I asked him for the story behind the picture; he shares:


KQWB, which was on 1550 at the time, added AM stereo when it was the big thing back in the 1980s. In the mid-’90s KQWB(AM) changed studio locations. From their then-new location, they couldn’t get a clear STL shot to the transmitter. So they installed an equalized phone line to the old studio, and then reused the old STL to the transmitter. The problem, however, is the phone line only supported one channel of audio. But since it was a talk station at the time, it wasn’t a huge deal, and they shut the AM stereo off.

In 2000, they got permission to move to expanded band AM, and go to 1660. Part of the deal with doing that was they had to keep AM stereo, so the new 1660 transmitter was ordered with the ability to do AM stereo (although stereo stayed off… not quite sure how that happened).

Fast forward to about two years ago. We were still using the phone line to the old STL to get our audio out there and we now have a music format. The current owners of the old studio where the STL transmit point is located gave us a two-year notice to vacate; we have to be out May 2015. So we started coming up with solutions to not only rebuild the STL but also get stereo back while we were at it.

Management didn’t really care either way about the AM stereo; but my partner in crime, Mark Borchert, and I both take the position that if we have the ability to be in AM stereo, we should do it. Unfortunately, a T1 or any sort of Internet is not available at the site (it’s quite a ways out of town), and even though we moved studios since, we still cannot get a clear STL shot to the transmitter.

Now, about two months ago, one of our FMs, KBVB, became the first in the market to go HD Radio. And since that site has Internet (and we’re running out of time to get an STL solution in place), we put KQWB’s audio on KBVB-HD3. We installed a Telos Z/IP One codec to go from the studio to the KBVB transmitter, installed an HD tuner at the AM transmitter site and we’re pulling the HD3 signal off air to put on the AM.

We just finished putting that in last week and we turned on the stereo pilot yesterday. The eventual plan is to find some sort of way to get a real STL or T1 link in place, but for now that will have to do.

As for the tuner, that belongs to Mark. It’s a Realistic TM-152. He brought it into the office so we could monitor the AM stereo signal. I actually had to open up the radio and tweak the receiver a bit so it could do 1660… its “limit” was 1630 and 1660 was just a little scratchy. A little adjusting of the IF and I got it dialed in perfectly. Besides the modulation monitor at the site, we don’t have any other radios that can do AM stereo.

And up until this morning I had never heard our station in AM stereo, so I was really excited to hear what it sounds like. Needless to say I’m now scouring eBay for more radios… ha! Very pleased with the sound.

Thanks to Jake. I love sharing fun engineering experiences with readers; write me at radioworld@nbmedia.com.


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