Long ago I remember using a home made meteorite detector made out of a hula hoop. They were popular maybe 30 years ago. It had headphones and when a meteorite entered the atmosphere you'd hear a "chirping" sound. I can't seem to find plans or even a reference to one on the internet. Can anyone else remember these and refer me to a schematic or build instructions?

Thanks!

 

I am not sure what you remember, but there appears to be no sense to the idea at all. Sorry to say you either misremember or it was nonsense.

There is nothing about a meteor that anything the size of a hula hoop would be able to distinguish.

Don't mean to be a downer, but the reason you can find nothing is because it doesn't exist.

(I would love to be shown wrong, but will not hold my breath. If you find something be sure to share it, I'll build one!)

 

It is a bit hard to imagine how it could work.

Bob

 

I am not sure what you remember, but there appears to be no sense to the idea at all. Sorry to say you either misremember or it was nonsense.

There is nothing about a meteor that anything the size of a hula hoop would be able to distinguish.

Don't mean to be a downer, but the reason you can find nothing is because it doesn't exist.

(I would love to be shown wrong, but will not hold my breath. If you find something be sure to share it, I'll build one!)

You won't be able to use a simple loop but you can detect the ionized trail with a good RF backscatter detector and signal analyzer.
https://en.wikipedia.org/wiki/Meteor_burst_communications

 

I think the device may be based on "meteor scatter". It is based on the fact that the meteor creates an ionised trail which reflects VHF radio signals. This is the results of searching for "meteorscater"

Les

 

You won't be able to use a simple loop but you can detect the ionized trail with a good RF backscatter detector and signal analyzer.
https://en.wikipedia.org/wiki/Meteor_burst_communications

Yes, meteor scatter isn't a meteor detector, but it could be the TS read something about receiving meteor scatter transmissions with a loop.

It could be.

But that's akin to saying you can make a moon detector because you listen to EME.

Good call, however.

 

What I recall is that meteorites, as they enter the atmosphere generate a plasma trail. As the trail cools it generates a low frequency radio burst. The hula hoop was used as a core and was wrapped by turns of wire. I presume there was some sort of analog signal amplifier and you'd hear the "chirp" on the headphones. Or, maybe it was a prank to see how many suckers would stand out on chilly nights holding a hula hoop and wearing headphones!

https://www.britastro.org/radio/downloads/The_Generation_of_VLF_Emissions_by_Meteors.pdf

 

What I recall is that meteorites, as they enter the atmosphere generate a plasma trail. As the trail cools it generates a low frequency radio burst. The hula hoop was used as a core and was wrapped by turns of wire. I presume there was some sort of analog signal amplifier and you'd hear the "chirp" on the headphones. Or, maybe it was a prank to see how many suckers would stand out on chilly nights holding a hula hoop and wearing headphones!

https://www.britastro.org/radio/downloads/The_Generation_of_VLF_Emissions_by_Meteors.pdf

Given the data in that paper, it seems marginally possible that during a meteor shower weak VLF events could be detected.

My skepticism, though, concerns a hula hoop sized loop antenna as the receiver. The frequency of interest is exceedingly low, and the directionality of a loop, combined with the low gain of something that compact, makes it seem impractical.

However, given the work shown in the paper, I retract the intensity of my skepticism, since there is specific, detectable energy. It may well be that if you can see the meteor shower, you can orient a directional, low gain antenna in such a way as to distinguish the signal from the noise.

If you can find a plan for a receiver that is as simple as you recall, certainly post it here!

 

It's also known as electrophonic meteors. The VLF wave can cause physical objects to vibrate causing a sound to be heard.
SG

 

Yes, meteor scatter isn't a meteor detector, but it could be the TS read something about receiving meteor scatter transmissions with a loop.

It could be.

But that's akin to saying you can make a moon detector because you listen to EME.

Good call, however.

Back in the days before total sat-com domination we used tropo and sometimes meteor scatter systems for medium-speed Defense Communications System (DCS) digital links.
http://www.vistapinas.com/article/mt-cabuyao-troposcatter-dishes

The Soviet / Russian Systems were pretty good too.

 

The hula-hoop was obviously an inductor- and responds to an EMF burst within a frequency range. The question is, is their such a burst upon a meteorite traveling at possibly tens of thousands of miles an hour hitting the atmosphere? Definitely not discounting the 'sucker' possibility.

(sghioto beat me to this):

However, this may fall into the field of electrophonics-- here is something that supports what you're saying, and may provide enough information about frequency that a circuit could be built--

https://m.tau.ac.il/~colin/research/Meteor/meteor.html

 

This is interesting: http://www.livemeteors.com

It's not direct reception of VLF, though. It depends on reflections in VHF and uses (apparently) a carefully aimed Yagi.

 

Found this. In 1949 they were listening to meteors so I guess I'm not completely crazy!

https://books.google.com/books?id=I...age&q=popular mechanics meteor listen&f=false

I'm no radio expert to be sure, but here's a crazy thought: I remember using this hula hoop gizmo in Minnesota, not terribly far from the Navy's ELF project. Could that have been the transmitter source for the low frequency "pinging" off the meteor trail? ELF was shut off about 15 years ago so with that gone maybe the hula hoop gizmo wouldn't work anymore so it faded into obscurity? Just a WA thought.

I also found this posting:
Re: Listening to meteors...

• Quote

#2 Postby Tetenterre » December 14th, 2014, 1:35 pm

Saw that on twitter. Nice. The good folk at the NLO also use radio scatter detecton; live feed here.

You don't actually need very sophisticated kit. I used to do it with a radio scanner, set to SSB and tuned to a TV1 carrier in SE Europe, using a simple home-made1/4 wave dipole in theloft as an antenna: you hear doppler "pings" off the ionisation trails.

But you don't even need to get as hi-tech as that: a simple FM reciever, tuned to an over-the-horizon transmitter (from the New Forest, BBC Radio Bristol works a treat) and you get short snatches of the broadcast as it reflects off the ionisation trail.

Could what I remember have been a receiver to pickup over the horizon ELF?

I'd love to hear more from you guys, even if its just ripping me. Its pretty interesting still!
Thanks

 

Found this. In 1949 they were listening to meteors so I guess I'm not completely crazy!

https://books.google.com/books?id=INkDAAAAMBAJ&pg=PA160&lpg=PA160&dq=popular+mechanics+meteor+listen&source=bl&ots=aR6Jeu05o4&sig=ACfU3U1QoqUqoa16WnVke3pmAjF_4dLxsA&hl=en&sa=X&ved=2ahUKEwi5iKeC_6fhAhUVuZ4KHXH5CtEQ6AEwDHoECAgQAQ#v=onepage&q=popular mechanics meteor listen&f=false

I'm no radio expert to be sure, but here's a crazy thought: I remember using this hula hoop gizmo in Minnesota, not terribly far from the Navy's ELF project. Could that have been the transmitter source for the low frequency "pinging" off the meteor trail? ELF was shut off about 15 years ago so with that gone maybe the hula hoop gizmo wouldn't work anymore so it faded into obscurity? Just a WA thought.

I also found this posting:
Re: Listening to meteors...

• Quote

#2 Postby Tetenterre » December 14th, 2014, 1:35 pm

Saw that on twitter. Nice. The good folk at the NLO also use radio scatter detecton; live feed here.

You don't actually need very sophisticated kit. I used to do it with a radio scanner, set to SSB and tuned to a TV1 carrier in SE Europe, using a simple home-made1/4 wave dipole in theloft as an antenna: you hear doppler "pings" off the ionisation trails.

But you don't even need to get as hi-tech as that: a simple FM reciever, tuned to an over-the-horizon transmitter (from the New Forest, BBC Radio Bristol works a treat) and you get short snatches of the broadcast as it reflects off the ionisation trail.

Could what I remember have been a receiver to pickup over the horizon ELF?

I'd love to hear more from you guys, even if its just ripping me. Its pretty interesting still!
Thanks

This is the meteor scatter method. It uses VHF, like the website I linked above.
VLF and ELF are such long wavelengths they need specialist antennas and receivers.

The suggestion that the hoop was an inductor in a tank circuit is possible but it would have to have very high Q, and it would be very narrow, so it depends on the reliability of the frequency and its energy.

The meteor scatter idea seems most likely, since there are many high powered transmitters operating at frequencies which will propagate via the ionization trails.

The paper you linked looked at both, I think, to correlate the VLF pulses with the meteor echoes (scatter, I believe, though I didn't read in depth).

 

Found this. In 1949 they were listening to meteors so I guess I'm not completely crazy!

You are not crazy at all! If I gave you the impression I was commenting on your sanity or being disrespectful, I sincerely apologize. Sorry about that, it surely isn't what I intended.

That story is about meteor scatter reception as well.

But, there are crazy people out there, and I found this very important informational article while searching for information on this topic that I do think needs to be shared!

https://texashoopcompany.com/blogs/news/2017-moon-phases-astronomical-events

[DISCLAIMER: the link above is provided for the sake of humor, and, if you can't work that out this disclaimer is aimed at you.]

 

What I recall is that meteorites, as they enter the atmosphere generate a plasma trail. As the trail cools it generates a low frequency radio burst. The hula hoop was used as a core and was wrapped by turns of wire. I presume there was some sort of analog signal amplifier and you'd hear the "chirp" on the headphones. Or, maybe it was a prank to see how many suckers would stand out on chilly nights holding a hula hoop and wearing headphones!

https://www.britastro.org/radio/downloads/The_Generation_of_VLF_Emissions_by_Meteors.pdf

I seem to recall hearing something like this before. I never built one, never saw one, never understood how it could be heard. But I DID hear, I think it was a NASA site, that meteors could be detected when they strike the atmosphere. Can they? I don't know. But I distinctly recall seeing (on TV) spaghetti trees. It was around April first.

 

Long ago I remember using a home made meteorite detector made out of a hula hoop. They were popular maybe 30 years ago. It had headphones and when a meteorite entered the atmosphere you'd hear a "chirping" sound. I can't seem to find plans or even a reference to one on the internet. Can anyone else remember these and refer me to a schematic or build instructions?

Thanks!

 

 

A coil with a number of turns inside a hoop and coupled to an amplifier that controlled the frequency of an oscillator could certainly respond to any disturbance. And that ionized trail does create a bit of disturbance. An amplifier with enough gain will deliver all kinds of interesting sounds with just a few feet of wire. I built one back about 1965. It had 2 stages with a claimed gain of 1000 each, a total of 60dB gain, driving a 6V6 output amplifier with a gain of about 15, I think. It would deliver clicks from the speaker from lightning flashes in distant storm clouds. With a good multi-turn loop I could probably have detected meteor bursts. But I lost interest in that and discovered that with a microphone I could hear more interesting things from the girls next door talking.

 

This is interesting: http://www.livemeteors.com

It's not direct reception of VLF, though. It depends on reflections in VHF and uses (apparently) a carefully aimed Yagi.

There is a site called Ping Jockey that is used to spot and make VHF QSOs on 6M and 2M using the scattering effect of hot ion trails. It uses a modulation method called FSK-441. It works over a typical distance of 1200 miles. Far in excess of normal VHF propagation.

https://www.pingjockey.net/cgi-bin/pingtalk
https://www.sigidwiki.com/wiki/FSK441