MadModder
The Breakroom => The Water Cooler => Topic started by: AdeV on March 17, 2018, 12:02:20 PM
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Have you ever had something completely unexpected, and quite possibly inexplicable happen to you?
Here at home, my computer is plugged into an amplifier & from there into 2 speakers. I also have a second input, which I plugged into my laptop. I couldn't get it to work (found out eventually the computer was sending audio own the HDMI cable to the speakerless monitor. Not terribly useful!), but whilst I was fiddling with the connection at the laptop end, I discovered that if I had it half-in, half-out of the laptop socket, I could hear a football match over the speakers!!! What's weird is, my amplifier is NOT a tuner amplifer, it doesn't have a radio in it at all. So what the hell was plucking a radio signal out of the air, demoduating it into amplifier-friendly signals to the point I could hear it!?!?
Note: It wasn't the laptop (once I figured the correct audio path, that works perfectly); and it only happened when it was literally half-in half-out of the laptop; unplug completely and it went away, plug in completely and it went away.
As the title of this thread says: Unexpected weirdness! Anyone else experienced anything like this? Or weirder?
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The BBC long wave transmitter at Rugby (198 Khz ?) when it was in use was pretty powerful. There were reports of peoples radiators in nearby houses demodulating the signal.
I assume the copper pipe to iron or steel radiator junction had some copper salt crystal acting as a rectifier :scratch: I think this transmitter also used (perhaps still does) carry the ULF signals used for transmission to submarines.
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Ade,
Many years ago (40+ years ago) I had a hi-fi system in my bedroom. My Mum complained that the FM radio downstairs was picking up the music I was playing on cassette upstairs.
For some reason my hi-fi was transmitting. If I repositioned the cable between the cassette deck and the amp it changed the frequency!
I managed to move the frequency away from broadcasting over radio 2 and could listen to music in the garage.
I've also heard of church organ pipes picking up radio signals.
Andrew - Where's the 198kHz signal being broadcast from now? In the early 80s I made a receiver to pick up the signal and then wrote a program in BBC Basic to decode it. I'll still have it all somewhere. (Inc. 3 BBC Model Bs!)
My wife and I were on a cycling trip last year and came across a derelict VLF radio station at Criggion near Welshpool. This was used for submarine communications at the time of the Falklands War. http://www.oswestry-history.co.uk/criggion-radio-station.html (http://www.oswestry-history.co.uk/criggion-radio-station.html)
Phil.
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Your Mum listened to Radio Two :bugeye: Good heavens man there is no hope for you :lol:
The Rugby Transmitter Aerial Farm was very visible going up the M1 about junction 18 /19 just before the Watford Gap Services. I don't travel like I used to so not sure if it's still there or has been replaced by endless boring 'different but the same' housing estates for the population of Eastern Europe !
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Your Mum listened to Radio Two :bugeye: Good heavens man there is no hope for you :lol:
The Rugby Transmitter Aerial Farm was very visible going up the M1 about junction 18 /19 just before the Watford Gap Services. I don't travel like I used to so not sure if it's still there or has been replaced by endless boring 'different but the same' housing estates for the population of Eastern Europe !
I must admit I listen to Radio 2 when I'm in the car. Can't be doing with Radio 1 with too much (C)Rap rubbish!
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You're DOOMED man :lol:
. . . . .prefer the Home Service personally :ddb:
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Rad 2 gets my vote too....Aint listened to R1 since my teens.....
Must be an age thing.. :coffee:
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Radio 1 didn't exist during my teens - it was The Light Program :clap:
Home Service - Radio 4 - but even that's gone down hill
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I listen to planet rock in the car and the workshop :thumbup: (that's the only places I can get away with it) the rest is classic FM my other half's domain. JD
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Congratulations, you made an amplified crystal set. ( remember them?)
A 'dirty' joint, with an oxide layer between, will act as a rectifier. (metal oxide rectifiers were common in battery chargers, welders, etc). A blued razorblade can be used to make a crystal set.
The partially plugged cable must have made a semiconducting joint, and a local station strong enough to create enough audio.
Russ
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Planet rock I thought that died will have to retune , Alis Cooper as a DJ was cool .
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Congratulations, you made an amplified crystal set. ( remember them?)
Coooool! Yes, I remember them (I never made one, though, sadly). Until now, that is :zap:
A 'dirty' joint, with an oxide layer between, will act as a rectifier. (metal oxide rectifiers were common in battery chargers, welders, etc). A blued razorblade can be used to make a crystal set.
The partially plugged cable must have made a semiconducting joint, and a local station strong enough to create enough audio.
I'm surprised at that. I thought the purpose of the crystal was to set the frequency you were tuned to?
Planet rock I thought that died will have to retune , Alis Cooper as a DJ was cool .
It's on DAB only as far as I'm aware. Along with a whole load of other "genre" stations - my wake-up-to station is "Absolute 80s". It's also crystal clear, unlike any FM station around here, which tends to fade in & out.
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A typical crystal set has a coil and a capacitor which set the frequency. Adjusting one or the other 'tunes' it.
The diode acts as a demodulator, extracting the audio from the Rf carrier.
Works great for am, tolerably well for fm.
Dab not a hope...
Am can cover long distances. So not necessarily a local station, especially with an amplifier in the picture.
I remember reading of people where a metal tooth filling acted as both the demodulator and the speaker.
Russ
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Yep planet rock is still alive and kicking on DAB radio :headbang: A good mix of all ages, AC/DC thru Slip Knot up to today's Rock/Metal :thumbup:.
JD