The first time radio engineer Joe Geerling approached a 12,000-kilowatt radio tower with a hot dog on the end of a stick wrapped in jumper cables, he had a pretty good idea of what would happen.
Geerling, the director of engineering at Covenant Network Catholic Radio, has spent decades working around radio towers and transmitters. He was familiar with this tower in St. Charles — and he knew that it had more than enough energy to injure anything, human or sausage.
Joe's son, Jeff Geerling, captured the moment on video for his popular tech channel on YouTube.
As the cooked sausage made contact with the tower, the Catholic radio station's broadcast crackled to life at ear-splitting volume. A voice emerged from the hot dog's burning flesh. The 2024 experiment went viral, gaining millions of views across multiple platforms.
"We did not know whether it would explode quickly," Joe Geerling said on "St. Louis on the Air." "For me it was the thought of: 'What is going to happen? How quick will it heat up? What will it do when it heats up?'"
The idea for the experiment had gripped both father and son since Jeff had first suggested it on a whim after passing by an AM radio tower. Their dual curiosities converged on the interaction between radio frequencies and a suitably substantial test subject. They quickly settled on a hot dog.
After they consulted with other radio experts and devised a safety plan, the Geerlings' experiment was ready. But neither of them predicted that it would turn the hot dog into an audio speaker, broadcasting the AM signal as it burned.
"The sound part of it was the shock," Joe Geerling admitted. "How clear when they're out there — it's loud too. It's a very loud sound."
"I thought it would just either explode, or not make any sound," added Jeff Geerling. "You see the video, and that's one thing. But when you're there and hear how loud it is, it's like somebody set up a speaker, a loudspeaker, and is blasting it at you."
Posted to Geerling's channels on YouTube, TikTok and Instagram, the first video and later sequels inspired copycats and visits from other notable science YouTubers. Joe and Jeff Geerling even tried other materials, including corn dogs and pickles, which similarly broadcast audio as the electricity burned them.
Nothing seemed to transmit sound as effectively as the hot dog.
"We came back multiple times to do more experiments, because once you do something and something unexpected happens, you have to go back," Jeff Geerling said. "We also measured the heat of the hot dog, and what I was surprised by was that the hot dog was not really heated up at all. … That RF signal was tunneling through it, so there was probably a little tunnel inside of it that was really hot."
But the Geerlings said they weren't sure how, exactly, the hot dog was generating sound.
"The comments really started it off, because a lot of people were saying, 'What causes that to happen?' And we didn't know," Jeff Geerling said. "Ultimately, a lot of the comments were saying, 'Maybe it's the plasma?' Like it's creating a little plasma conduit between the tower and the hot dog. That could be a plasma arc causing the audio."
The Geerlings weren't the only ones hooked by the mystery of the "talking" hot dog.
In November, Gavin Free, founder of YouTube channel the Slow Mo Guys, used a specialized camera to capture the arcs of plasma leaping from radio tower to hot dog at 200,000 frames per second — turning a momentary flash into dozens of seconds of video footage.
When the video is slowed down, plasma can be seen ripping chunks of hot dog apart. To Jeff Geerling, they looked like "mininuclear explosions."
Earlier in 2024, Jay Bowles, founder of the Plasma Channel, traveled to the tower to test his own theories for "stealing" RF energy by converting it into electricity.
That a radio tower and hot dog attracted such a flurry of public interest is a testament to ongoing fascination with technology and electricity, said Jeff Geerling, who has more than a million subscribers on his channel Geerling Engineering.
"There's a lot of people with a great amount of curiosity, and the thing that I like the most is everybody seems to be there to build each other up," he said. "Like with this whole tower situation. Everybody is building on top of it, and you can find something new about physics or about electricity or RF just based on one dumb experiment that we did."
However, the experiment at this particular tower has come to an end. Two years removed from that first video, Joe Geerling said the radio tower's owner has restricted access for any further investigations.
But Jeff Geerling is still curious.
"We have been talking with various transmitter manufacturers," he said. "We want to do higher-power experiments, which may be possible if we go to the places where they test these things."
To hear the full conversation with Joe and Jeff Geerling, listen to "St. Louis on the Air" on Apple Podcasts, Spotify, or YouTube or click the play button below.
"St. Louis on the Air" brings you the stories of St. Louis and the people who live, work and create in our region. The show is produced by Miya Norfleet, Emily Woodbury, Danny Wicentowski, Elaine Cha and Alex Heuer. Danny Osborn is our production assistant. The audio engineer is Aaron Doerr.
Copyright 2026 St. Louis Public Radio
