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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

#101

Post by jdironman »

FiatLuxDave wrote: post #91
SoftTalker wrote: post #72

Earlier quoted context omitted.

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 tol…

Well, your comment was my deep laugh for the day. excellent story. When I was younger, I saw my father working on a ceiling fan...while it was on. I asked him why he did not flip the breaker first and he said "well, as long as you don't touch both wires at the same time, you'll be fine "

Fast forward a few days later I am at school, and I see in one of the outlets one of the prongs for a power cable had broken off in it. I remembered his advice about not touching both sides and proceeded to try and pull it out using my fingers...you can probably imagine what happened. It grabbed hold of me for a few seconds and a lesson was learned.

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

#102

Post by retrac »

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

It's also possible to detect the presence of an AM transmission (if not necessarily decode) at a much lower received power than with FM. With FM there's little in the way of graceful degradation. As signal strength falls it can go from full fidelity to silence with very little transition.

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

#103

Post by mike_hearn »

bityard wrote: post #82
eternauta3k wrote: post #49

Earlier quoted context omitted.

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…

https://www.youtube.com/watch?v=oBJyyEAw-6g

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

#104

Post by fortran77 »

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…

Cement is surpisingly conductive. I have a thick rubber mat I stand on when doing high voltage (CRT, etc) repair work, and even then I have a full set of rated protective gear, and precautions (one hand in pocket, etc)

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

#106

Post by [deleted] »

ck2 wrote: post #73
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…

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…

[deleted]

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

#107

Post by dumbo-octopus »

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

This makes AM radio more fun to listen to, as you get knobs for both your radio and your mental “tuner”. At night, you can pretty consistently hear 3+ broadcasts at once, and listen to them all simultaneously a la overhearing many conversations at once in a busy room.

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

#108

Post by walrus01 »

As a sort of a side note for everyone who thinks AM radio is dead as a useful medium, they've probably never lived and driven a car in a city that has:

(a) a 50kW AM radio station with frequent and accurate traffic updates, often much better detail than what you can get from using google maps or waze or similar, and

(b) massive, frequent traffic problems and congestion at major bridge and tunnel locations.

It's still a very useful thing to have when driving and you don't need to take your eyes off the road at all.

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

#109

Post by SoftTalker »

jdironman wrote: post #101
FiatLuxDave wrote: post #91

Earlier quoted context omitted.

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 tol…

Well, your comment was my deep laugh for the day. excellent story. When I was younger, I saw my father working on a ceiling fan...while it was on. I asked him why he did not flip the breaker first and he said "well, as long as you don't touch both wires at the same time, you'll be fine " Fast forward a few days later I am at school, and I see in one of the outlets one of the prongs for a power cable had broken off in…

In theory, if you were wearing rubber shoes and not touching any other path to ground, you would have been fine.

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

#110

Post by hermitcrab »

timr wrote: post #71
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…

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…

I had no idea that radio towers used that sort of ampage.
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