2. analog
  3. 127317-5312

Periodic noise

My system picks up noise every eight minutes. There is a kind of scratching mid-register ("ta-ra-ta-ta") sound that last for ten or fifteen seconds. It is similar to descriptions of "GSM buzz" but it happens regularly and regardless of whether our mobile phones are on or off. It happens when the analog source is selected, not other sources (or not obvious, in my system). It is very clear when the volume is mid-high, with no music playing. It is not from the cartridge and the tonearm cable, since it happens even when I disconnect them from the phono stage. When I disconnect the phono stage, however, I don't hear it. So it seems to be picked up from the phono stage itself. It happens across different phono stages. Shielding the cables with ferrite does not help much. It seems like a very strong signal.

Anyone recognizes this problem?
o_holter
czarivey
5,946 posts
 
Someone is trying to tap your phone.
iPhones are less-likely to be traceable and provide the best privacy
dover
2,353 posts
 
You might want to check whether your main power board has a smart meter that monitors power usage and transmits power usage info back to supplier at regular intervals.
Alternatively the source could be from neighbours, there are so many sources for wifi these days - routers, phones, many household appliances now have wifi active.

o_holter OP
980 posts
 
almarg - you were right. I unplugged the main alarm system control box and disconnected the battery. Now, the noise was gone. I will get service on the system tomorrow. It is both wired and wireless.
lewm
13,778 posts
 
My wife signed us up for Verizon Fios.  At one point, the Fios was going down with regularity, until I finally investigated our circuit breaker box, where they had installed an AC outlet to power their system, which is a simple plug-in.  It was easy to demonstrate that power to the plug was intermittent, by simply wiggling the plug, causing our problem with lost service.  When I opened the housing for the new AC outlet their tech had installed, I found that the wires were nearly floating free in the box, just barely in contact with the outlet, because of sloppy attention to detail.  At least it was easy to fix.  Then I noticed that the Verizon crew had tapped into my dedicated AC lines to power the new outlet they installed for Fios, thus assuring that my audio AC was constantly polluted with digital garbage. You've gotta keep an eye on these installers.

o_holter OP
980 posts
 
The solution so far - the installer moved the box out of the room with the stereo system, and up to the second floor of the house. Now the noise was gone. It comes from the GSM chip in the controller box (made by Honeywell) he told me.
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