broadcast

Nearing it's centennial, KMOX-AM (1120 kHz) is a 50,000-watt clear-channel AM radio station with studios located in downtown St. Louis, MO, USA.

But their broadcast tower is located about 10 miles northeast, in Pontoon Beach, IL. My Dad was the director of engineering overseeing the tower and studios for about 20 years, and though he's no longer there, he and I got permission from Audacy and the St. Louis engineers (thanks!) to tour the site, and learn a bit about how they broadcast their AM signal—which reaches all the way into Canada and Mexico at night!

In this blog post, I'll write a bit about KMOX's tower system (AM towers are a lot different than FM, like the FM Supertower we toured last year), the transmitter, and the some of the history found at that tower site.

KSDK-TV broadcasts to well over 1 million households in the St. Louis metro area. And my Dad and I went to their broadcast tower last month to explore how the digital TV signal is delivered through the air to so many people.

On our tour, we explored over 75 years of television broadcast history, seeing how things transitioned from thousands of volts down to hundreds, and from analog audio and video to all-digital.

And we even found strange artifacts of the past, like this random microwave dish that received a signal through the roof of the broadcast building for a time:

My Dad and I just posted a new video on the Geerling Engineering YouTube channel where we explored the tallest radio tower in the St. Louis metro area, the so-called 'Supertower' that has a 10-station combined dual FM antenna system (dual 4-bay FMVee by Dielectric) at the top: