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Punk Rock bracelet
Posted: Tue Feb 18, 2020 6:08 pm
by Rich4349
... And not for fashion sense, but for subversiveness.
When can we expect the BFM design of these? (Sorta related to the UK's anti-loitering-teenager devices.)
https://gizmodo.com/the-studs-on-this-p ... 1841768759
This tweeter runs up to 40kHz, draws 5 watts (no idea on voltage), and has 86 dB sensitivity.
https://www.parts-express.com/tang-band ... --264-8016
There are about about 8 others that go up to 25-40, Daytons and TB.
Re: Punk Rock bracelet
Posted: Tue Feb 18, 2020 9:17 pm
by jimbo7
I was recently working at an air force base communications building that had these shoe-box sized boxes every 15 feet above the grid ceiling that made white noise. I asked a sparky what those boxes were and he said they're just speakers to make white noise to prevent eavesdropping in the attic above. I was wondering what that faint hiss sound I kept hearing was. I'm sure our overlords are perfecting brain wave communication surveillance as we speak.
Re: Punk Rock bracelet
Posted: Tue Feb 18, 2020 9:49 pm
by Bryan Cox
jimbo7 wrote: ↑Tue Feb 18, 2020 9:17 pm
I was recently working at an air force base communications building that had these shoe-box sized boxes every 15 feet above the grid ceiling that made white noise. I asked a sparky what those boxes were and he said they're just speakers to make white noise to prevent eavesdropping in the attic above. I was wondering what that faint hiss sound I kept hearing was. I'm sure our overlords are perfecting brain wave communication surveillance as we speak.
Yeah we have those all over, especially in rooms cleared for processing of classified info.
Re: Punk Rock bracelet
Posted: Tue Feb 18, 2020 9:50 pm
by Bryan Cox
Hey I just noticed you're from St. Louis. Were you doing work at Scott or White man? I ask because I'm from the Jefferson City/Rolla area.
Re: Punk Rock bracelet
Posted: Tue Feb 18, 2020 11:50 pm
by Strange Kevin
Not that I'm a spy....
But, I had a thought,
would It be possible to find the inverse of white noise to cancel it back out? Like the common mode rejection on an XLR? Leaving only the audio you wanted to hear?
I know it wouldn't be that easy, but is there a chance?
Please, Dont report me, I'm just curious!
Re: Punk Rock bracelet
Posted: Wed Feb 19, 2020 2:00 pm
by Bryan Cox
That sounds more like a question for Bill. But I believe it is possible.
Re: Punk Rock bracelet
Posted: Wed Feb 19, 2020 7:07 pm
by jimbo7
Bryan Cox wrote: ↑Tue Feb 18, 2020 9:50 pm
Hey I just noticed you're from St. Louis. Were you doing work at Scott or White man? I ask because I'm from the Jefferson City/Rolla area.
Scott