If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
HFsstc-freak wrote ...
I filtered your file, here it is: <-- 216.6Hz bursts randomly placed.
Hear you can decodethe message heard:
I've read the PDF and now I understand what is it. The signal is though quite powerful and sometimes disturbing, I wonder how such big distortion of mains waveform is allowed...
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
EastVoltResearch wrote ...
Regardless of where the source is originating from, what you are hearing is the core vibrating.
Yes, this was in the first recording. In the second one I used a resistor divider to soundcard line-in, this way I recorded the actual mains waveform not the vibration of the core.
Registered Member #621
Joined: Sun Apr 01 2007, 12:37AM
Location:
Posts: 119
This is funny that I saw this post, as I have been puzzled for nearly a year myself with a similar odd "resonance" In my room i have a stereo system in which the amplifier used to sit in standby mode when i was sleeping. At random times during the night I would hear a buzz coming from my speakers, from my ceiling fans motor, and the LED on the stereo that indicates it is getting signal from a remote would flash at a very high rate. Still does this and randomly. I shut the amp down completely now so it doesnt wake me, but with the ceiling fan doing it too i know it must be a mains thing!
Registered Member #599
Joined: Thu Mar 22 2007, 07:40PM
Location: Northern Finland, Rovaniemi
Posts: 624
MikeT1982 wrote ...
This is funny that I saw this post, as I have been puzzled for nearly a year myself with a similar odd "resonance" In my room i have a stereo system in which the amplifier used to sit in standby mode when i was sleeping. At random times during the night I would hear a buzz coming from my speakers, from my ceiling fans motor, and the LED on the stereo that indicates it is getting signal from a remote would flash at a very high rate. Still does this and randomly. I shut the amp down completely now so it doesnt wake me, but with the ceiling fan doing it too i know it must be a mains thing!
I have almost same thing here, it has been like that as far as i can remember. At night (i think it happens daytime too but you cant hear it) very high pitch sound appears from somewhere like iii...iiiiiiii...iii.iiiiiiii and disappears. First i thought its just my old CRT monitor, replaced that but sound is still here. Then i thought that it has to be PSU from my computer. It wasn't that either. Every single electrical equipment has been changed in this room since i first noticed this sound. And that sound is still there.
Registered Member #621
Joined: Sun Apr 01 2007, 12:37AM
Location:
Posts: 119
Yeah man, I wish I had an O-scope to visualize it, eventually I want to buy one darn. From the soudn of it, it definitely isn't a smooth sine wave, i'd guess it is a square wave or sawtooth, it sounds like it. I wonder if it is from the utility company or if it is actually another appliance in the house like a refrigerator kicking on. The odd thing is that it starts out quiet for about 5 seconds, then get double the intensity and thats when the fan motor buzzes and the speakers would gain intensity, and my stereos infrared remote sensor would flash more intensly! How the heck the EMF waves affect the infrared sensor puzzles me. It doesn't make the stereo run through any functions but the infrared remote sensor flashes indicating it is recieving infrared waves....hmmm. Darn I wish I had a scope. I live on farm roads, and I can't remember this happening before last summer when the installed a large Pole pig looking (huge pole pig) device down the road on a random pole. i took a drive down and it is on an abandoned farm road and reads Seimen's Voltage Regulator. I wonder if it is cooincidence or if this has anything to do with it.
... not Russel! Registered Member #1
Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052
Attached is a spectrogram of the longer file that jmartis provided. I almost immediately recognized the presence of a start bit -- the long pulse -- followed by data bits. This is very similar to radioteletype (rtty) signals. According to the pdf linked above, each device would be assigned a code, and since the stream can be 44 bits long, many millions of devices can be issued various commands in this manner.
The downside, as you can see, is that the resulting signal ends up with many many harmonics. Also, apparently, people can hear the signal in their applicanes.
Mystery solved! And by the looks of it, similar systems are in place elsewhere.
Registered Member #396
Joined: Wed Apr 19 2006, 12:55AM
Location: Pittsburgh, PA
Posts: 176
Sorry for my ignorance, but am I the only person that can't read that PDF expect for the abstract? Am I missing a secret English part or is everyone simply understanding it from the diagrams?
Registered Member #941
Joined: Sun Aug 05 2007, 10:09AM
Location: in a swedish junk pile
Posts: 497
I think we have something similar in sweden, i dident notice anything until i ordered this transformer from my work for an amp, when i plugged it in i could clearly hear it buzz in different amplitudes, from quiet to irritatingly loud as in varying dc offset on the grid. These amplitudes varies in the span of a minute or two.
Tho i have never heard it with any of my other transformers, excepta contactor in the basement buzzing loudly sometimes/year
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
Strange mains waveform/"rattling" noise
