Vintage Technology: The Coherer

[@anverHisham]

Wow. Great illustration. Thanks a lot :-)

[@YuanLiuTheDoc]

This is so cool! I only saw a coherer in a museum.

[@2150dalek]

I never heard of this technology..Thank you for your intriguing presentation.

[@bixanorak]

I love 'old tech' & tinker with bits of it - but your video is the coolest thing I've seen for years. Absolutely marvellously simple & totally functional. Congratulations! Norman G4LQF.

[@kolinevans9127]

Ha I must have missed this one lol Great video

[@sangeeth_619]

Wow, really amazing video! never even thought such simple household items can be used like this! Thanks for sharing.

[@jonni2734]

AWESOME video!! Thank you!!

[@casanodininsik584]

Wow! simple a project but great source of idea... thanks

[@IIDECMNH]

It seems magic !

[@lambda4931]

Very cool. Thanks for the info

[@cobbiesmith9267]

Great video. Very interesting device. I did a little research, cool stuff. Very easy to build, worked first time. With spring around the corner, thunderstorms, going to try a simple lightning detector. Thanks for sharing another great project.

[@ludicscience]

Cobbie Smith Yes a lightning detector would great!

[@tedsimpson2174]

Excellent demonstration! In replicating the antennas used by Hertz I built several coherers that worked OK, but yours is better! Right now I am planning of making a video similar to yours, more technical, perhaps, but not as clever I am sure! Now I have the added task of replicating your demonstration to entertain dinner guest in candlelight after dessert and port wine is served!

[@EsamoKoram]

This could be used to find the best spot for antenna. But some kind of wavelength selector would be needed.

[@randommadguy]

Good video

[@kannants2651]

Nicest explanation

[@ludicscience]

Thanks

[@kruppstahl1686]

Thanks for the video. I made similar expeiments and recognized the following: You can use the coherer as a noise/ vibration amplifier. With a small power source, and in series to a seperation-transformer (for limiting the current) you can connect a headphone to the secondary(low ohm) to hear the amplified noises. I could imagine to build a very simple vinyl-player with this setup, by attaching a needle to the casing of the coherer. Something like a surveillance device could also be possible. Maybe you want to try it...

[@ludicscience]

helut kuno Sounds very interesting! I will definitely try that, thanks for your input.

[@sandisliepa984]

Carbon rods/discs may work as amplifier too. First non semiconductor time carbon microphones are very popular. Sovjet disc phones used carbon dust microphones in late 1980. Sometimes little noisy, but amplification are big

[@AjinkyaMahajan]

Great stuff. Was searching for coherent since long Can you also share how exactly the EM waves affect iron filing resistance

[@ludicscience]

thank you

[@DuaneVT]

In practice, they used a vibrating tapper to unpack the filings as they kind of latch on. I think that the filings have a higher resistance until the current pulse creates a corresponding magnetic field that aligns them to conduct better, more mag flux, better alignment, higher current......I think that is the reason for iron...magnetic...filings.

[@MultiHuze]

Awesome dude

[@unicycle332]

wow this is realy interesting

[@thunderbry]

Would a 9V battery work, with copper wires connected to the positive and negative terminals of the 9V?

[@gristlevonraben]

Very awesome

[@das250250]

Have you measured the induced voltage from the antenna onto the coherer. The coherer is a very odd mechanism , i would have guessed it would produce a short circuit all the time

[@ludicscience]

I didn´t

[@DuaneVT]

In practice, they used a vibrating tapper to unpack the filings as they kind of latch on. I think that the filings have a higher resistance until the current pulse creates a corresponding magnetic field that aligns them to conduct better, more mag flux, better alignment, higher current......I think that is the reason for iron...magnetic...filings.

[@malebitsatimbuktu3352]

Wow!

[@SUPERTROYANO666]

Lo are, se ve interezante

[@unicycle332]

could you have this work with specific frequencies?

[@ludicscience]

Matthew Corfiatis No

[@unicycle332]

would have been useful if you could, damn thanks

[@tingtong3697]

Matthew

[@DuaneVT]

The coherer itself is frequency independent. If you connected an inline series L-C filter tuned to show low impedance/high current at a specific freq, that SHOULD make it tunable. But it stays conducting after the first exposure to the antenna impulse.

[@icorteso]

Could this coherer handle significant amounts of current? I imagine that it is very limited due to the iron fillings.

[@ludicscience]

idakid Yes you are right. Only small currents

[@mimoslavija]

you can connect a relay or a transistor

[@aracknidd]

Fascinating, the way the iron filing aligned in the presence of RF seems similar to how piezoelectric crystals align in a crystal cell battery. The Coherer allows an existing current to flow in a circuit while piezoelectric crystal injects the current to flow in a circuit which is sourced from the RF. Both require some kind of connective alignment to be formed. Whats also interesting is when a Coherer is knocked it stops, while piezoelectric may start or continue current flow.

[@ludicscience]

Spangley Rainbows It is very interesting indeed, as far as I know, even today the mechanism by which the iron filings bvecome conductive in an RF field is not well undesrtood.

[@mimoslavija]

great thing i can detect lightning at a distance of 2 km (but i need 10 m long antenna)

[@charisellim3754]

How much volts do i need

[@ludicscience]

charisel christian 6 volts

[@spandandutta2485]

owseome experiment

[@_P0tat07_]

Mind fuck. That's so cool

[@alliswell0008]

It don't work from far away of 1 feet..only work in distance of 1 cm ...my project not working ....ohhhh

[@mimoslavija]

Hi! if you want to know how you can extend the range to a few meters, contact me on instagram, my name is mimoslovenski.izumi

[@alliswell0008]

Please reply me

[@udhi_gn3893]

Ignorant who doesn't know electronics will quickly comment this as "fake"

[@stevegelnett4469]

I'm agog.