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

jeffgeerling.com

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

#81

Post by dgacmu »

bArray wrote: post #67
dgacmu wrote: post #45

Earlier quoted context omitted.

The reason for licensing is similar to the reason for licensing ham radio: you get a slightly higher level of clue about not creating huge amounts of accidental interference, and a point of contact to yell at if they do. and a little safety education.... The ham radio licensing process is not onerous.

I went through it (admittedly many years ago), but ham licensing wouldn't really do anything for safe radio operation. I learned the real stuff from two very experienced operators. It would probably be easiest to regulate the transmitters than the people using them.

Me too, but at least there's some stuff in there (for extra) about RF safety. Not a lot, but enough that someone with an extra class license should know that they need to go do some calculations about the safe distance from their antenna based upon radiated power, etc., and hopefully that's enough to get them to actually do it. IIRC there was a question or two in the pool about RF burns.

Not much in there that would stop you from electrocuting yourself, though, I agree.

Licensing the transmitters is the FCC's other standard approach and would probably work except for radiated power safety and antenna issues -- which can be pretty big. You could easily create significant interference or hazard from a botched antenna or connection. (But also which you don't learn enough from just passing the exam.)

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

#82

Post by bityard »

eternauta3k wrote: post #49
bjornsing wrote: post #26

A grounded pickle. The word grounded is very important here, and missing from the question in the title.

I wonder if a floating human would still get zapped, due to its non-trivial capacitance to ground.

Not to do with RF, but there are old YT videos of HV linemen who literally hop out a helicopter onto an HV transmission line to manually inspect it. As the helicopter approaches, they hold out a long pole which is bonded to the aircraft's frame to bring it to the same potential as the line. It starts arcing quite a few feet out until the potential is neutralized and the lineman can "safely" step out onto the line and start working.

I imagine this inspection work is done with camera-equipped quadcopters nowadays.

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

#83

Post by MisterTea »

geerlingguy wrote: post #75
timr wrote: 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.

> electrocution-style burns

Do you mean burning via resistive heat dissipation from current flow through flesh? There are also burns from plasma in arc discharge events. An arc discharge to the body can produce both.

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

#84

Post by gosub100 »

JohnMakin wrote: post #39

I always wonder if there would be any pain in the death that results from touching one of these. I’d assume it’d be instant from the electricity traveling through your heart - or would you just burn up more slowly?

it may not kill you. the ways that electricity harms the body is unpredictable. Depends on things like bare skin vs gloves, humidity, sweat, what phase your heart is in at that exact moment, and probably many more factors. since the voltage is oscillating very quickly, it _may_ not cause your muscles to lock up, so you _may_ just get the zap of your life and bounce off. Whereas other types (non-RF) electrocution cause the muscles to lockup and for them to remain in contact with the voltage, which increases the chances of death.

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

#85

Post by timr »

geerlingguy wrote: post #75
timr wrote: 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.

Definitely, but this video is not that.

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

#86

Post by CobrastanJorji »

JCM9 wrote: 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?

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

#87

Post by K7PJP »

CobrastanJorji wrote: post #86
JCM9 wrote: 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?

AM doesn’t exhibit the capture effect, so you can hear multiple transmissions at once. https://en.m.wikipedia.org/wiki/Capture_effect

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

#88

Post by justanother »

SoftTalker wrote: post #72
justanother wrote: post #40

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)

Yeah, I try to bleed it with a long-handle screwdriver for 30 seconds. In fact, the couple times I've managed to zap myself was with residual current even after that, so I can't imagine what the full potential is. It's just a no-fun job.

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

#89

Post by gwbas1c »

K7PJP wrote: post #87
CobrastanJorji wrote: post #86

Earlier quoted context omitted.

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?

AM doesn’t exhibit the capture effect, so you can hear multiple transmissions at once. https://en.m.wikipedia.org/wiki/Capture_effect

> The ability to receive multiple signals simultaneously is in some cases considered beneficial and is one reason that the aviation industry, and others, have chosen to use AM rather than FM for communications.

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

#90

Post by linuxguy2 »

geerlingguy wrote: post #46
pewu wrote: post #16

Earlier quoted context omitted.

There's a broader area protected by a high fence with barbed wire. They had access there, cause the father is a radio engineer and have friends on various sites.

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!
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