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What happens when you touch a pickle to an AM radio tower

jeffgeerling.com

91–100 of 137 posts

Re: What happens when you touch a pickle to an AM radio tower

#91

I understand he got permission and everything was checked out by actual RF eggheads, but damn. I won't even change a HV run capacitor unless i'm wearing crocs, standing on cement, and wearing the rubber oven mitts. And even then, I keep one hand behind my back. Because there have been accidents, and they hurt (the pool pump run cap fails approximately annually in this climate and if I paid someone to change it every…

Just short the terminals with a screwdriver before you touch anything else? (Look away in case there's an brief arc flash)

Oh man, that reminds me of a mistake I made a few years back.

I had opened up a motor controller to fix it, and I knew to discharge the cap before messing around inside. I applied a screwdriver across the terminals to short it out, and was rewarded with a beautiful long and skinny arc as the screwdriver came into contact. I said out loud, "That was cool", and my coworker sitting behind me said, "What was cool"? I told him that I had just shorted out the cap and the arc looked really cool. So he said, "Can you show me?" I said sure, and plugged the controller in for a few seconds to recharge it, then unplugged it and proceeded to repeat what I had just done.

What I had forgotten was that previously the motor controller had been unplugged overnight. When I touched the screwdriver to the freshly charged capacitor, there was a boom, a three inch fireball, and the end of the screwdriver was completely gone. As I sat there thunderstruck, my coworker said, "You're right. That was pretty cool".

Re: What happens when you touch a pickle to an AM radio tower

#92
post #71

Earlier quoted context omitted.

Another thing to note, since people seem to be focusing on the RF aspect of this: there's 20-30 Amps running to the tower in this video. If your body is the connection to ground for a 20 Amp current, from any source, you're going to have a lot more to worry about than a burnt pickle (I guess it's cool that you'd make radio sounds while you died?) When they put the pickle/hotdog/whatever an inch away from the tower wi…

RF burns are a lot different than electrocution-style burns, though. But I'm not an expert on either topic, I'd defer to some people who know more about it.

Anecdotal: I was cooked by some pretty powerful ECM [electronics countermeasures] gear, because an ECM officer was dumb and had his equipment turned on while on the tarmac. My abdomen was up against the area where the antenna was, about 6 inches away.

No outward signs of injury, I just felt an internal burning sensation and severe nausea pretty quickly. I was feeling okay after about a day or two. I never did get checked out by medical, so no clue of what permanent damage was done.

Re: What happens when you touch a pickle to an AM radio tower

#93
A thing that just happened in Boston is that Bloomberg swapped their relatively low power transmitters with iHeart's Alternative Rock 92.9. This is awesome for Bloomberg's reach, but it means that we now have an AM rock station, probably for the first time since the 1960s: 1330 AM. We'll see how long this lasts.. Red Hot Chili Peppers on AM right now..

Re: What happens when you touch a pickle to an AM radio tower

#94
post #85

Earlier quoted context omitted.

RF burns are a lot different than electrocution-style burns, though. But I'm not an expert on either topic, I'd defer to some people who know more about it.

Definitely, but this video is not that.

Same disclaimer: I'm not an expert on this... but I have been talking a lot about RF burns and arcing with RF engineers, and I think there's more nuance to this.

It would be interesting to see the difference grounding a hot dog through 7 kW AC (60 Hz) and seeing any difference in internal heating and arcing. Maybe a topic to explore in another video—especially if I can get access to a transmitter manufacturer's testing lab...

Re: What happens when you touch a pickle to an AM radio tower

#96

Earlier quoted context omitted.

It's also in bordered by two farms, with a flood plain across the street, in a rural part of St. Charles County, in MO. Granted, home builders keep building subdivisions closer and closer, but just 10-15 years ago the closest residence was a mile or so away (outside the couple farm houses). There's also danger/warning signage around the entire property, on all fences (including those around the towers).

Is that the KH0J transmitter? I've driven past that countless times and it seems so run-down I've often wondered if it was still transmitting. So many times I've wanted to park in the lot and take a gander... Probably for the better that I haven't!

Yep! Honestly this site is about average in terms of local tower site upkeep. Many station owners let their sites run a bit wild, unfortunately.

Re: What happens when you touch a pickle to an AM radio tower

#97
post #78
post #19

Earlier quoted context omitted.

"WRL Technical Note TN-13 Characterization of Organic Illumination Systems" https://simh.trailing-edge.com/semi/docs/WRL-TN-13.pdf

One of the authors, Alan Eustace, was an exec at Google (in the days when execs at Google had a clue) and also holds the record for highest jump (135K feet).

Bill Gates can actually jump over a chair. og Tech execs are awesome at jumping it seems!

Re: What happens when you touch a pickle to an AM radio tower

#98
post #73
post #62

For folks wondering why these sort of videos (there are lots on YouTube) always focus on AM towers: 1. On AM the radio energy literally pulses (the amplitude modulation) and thus the arcs of plasma will pulse too thus creating the audio noise. AM has a carrier wave that’s constant but the two sidebands of signal pulse from zero energy at silence to more power the louder the sound being transmitted. FM signals broadca…

The history of AM radio and the invention of the mechanical sparkgap transmitters by Reginald Fessenden is absolutely fascinating. Imagine only having telegraphs and morse code and amateurs listening every night to the spark noises in morse then suddenly in 1906 (first done in 1900 !) you hear voices and music! https://en.m.wikipedia.org/wiki/Reginald_Fessenden can't seem to direct link the photos but scroll down to…

You can still see operating Alexanderson Alternators running at SAQ (Grimeton Radio Station). Not AM, but the same equipment was used for AM by Fessenden.

https://en.wikipedia.org/wiki/Alexanderson_alternator

https://www.youtube.com/watch?v=yYZjz745yGA

Re: What happens when you touch a pickle to an AM radio tower

#99
post #62

For folks wondering why these sort of videos (there are lots on YouTube) always focus on AM towers: 1. On AM the radio energy literally pulses (the amplitude modulation) and thus the arcs of plasma will pulse too thus creating the audio noise. AM has a carrier wave that’s constant but the two sidebands of signal pulse from zero energy at silence to more power the louder the sound being transmitted. FM signals broadca…

Why would we want aviation radios to operate in AM? Is it just that we standardized on AM before the 60s, it works well enough, and migrating would require a worldwide effort? Or is there some interesting advantage to AM for planes? Maybe superior range?

One reason is that AM signals blend together whereas with FM the stronger signal will tend to "capture" the others and be the only one heard. This matters a lot in busy airspace where multiple people may be talking simultaneously.

Re: What happens when you touch a pickle to an AM radio tower

#100

What I didn't see explained in these videos, and which I'm now curious about, is the mechanism by which the hot dogs convert the radio signal into sound? I understand how a loudspeaker works, but since food products typically don't contain coils and magnets, how was the AM signal being demodulated and converted into sound waves?

I haven't watched it yet, but they state in the beginning of Geerling's vid that Plasma Channel (run by the third guy in the video) should be covering this in their own simul-published video.

https://www.youtube.com/watch?v=NowhPAMDOTo

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