4 ms·

Time to get your own isolated grid huh? Maybe with solar and inverters?

by atoav 4y ago

deleted 4y ago
[deleted]
ratww 4y ago
An on-line UPS like those used in datacenters or music studios is probably enough. They basically have rectifiers and inverters in them. Some of them have phase-locked loops to sync the output frequency with the mains, but probably won't stray as far from 50Hz (or 60Hz) as the mains themselves seem to do. If they do, unplugging the mains and using the battery is probably enough to get pure 50Hz back!
- jsjohnst 4y ago
  > An on-line UPS like those used in datacenters or music studios is probably enough. Only if you don’t have mains power anywhere near the recording device. You don’t need to be plugged into mains power to have it be present in a recording.
  - ratww 4y ago
    True! And that applies for every case. Even if you have 100% isolated mains with solar or battery, you'll get 50hz from neighbours (especially apartments) and power lines close by. I remember having this issue when working in a recording studio during college, even when we switched to battery and turn the mains off, we'd still get hum in some guitars. Funny enough I was recently reading an interview with producer Michael Beinhorn and he mentioned having some "mystery EMF/RFI event" happening in New York around 1997, coming from a specific block, and he had to relocate a recording session to Los Angeles because of how strong it was interfering with the guitar amps and other equipment [1]. [1] https://gearspace.com/board/interviews/1385579-interview-michael-beinhorn.html#vw-head-80 https://gearspace.com/board/interviews/1385579-interview-mic...
    - jsjohnst 4y ago
      I really wish this story included which half block area it was strongest.
      - ratww 4y ago
        That would be very interesting to know! Especially considering the two studios he mentioned aren't exactly close to each other: https://goo.gl/maps/MLw3twvRi9GumYeX8 https://goo.gl/maps/MLw3twvRi9GumYeX8
s0rce 4y ago
You'd need to make sure there is no grid nearby. If you were completely off-grid and away from power lines or anything then you'd have no signal at the mains frequency. Certainly possible. Probably easier to just use a filter to mask the frequency component.
ris 4y ago
Probably better to run a decoy signal (or two) in the background with similar characteristics.
pugworthy 4y ago
To what end? What do you want to obfuscate by doing this?
- coldtea 4y ago
  https://www.aclu.org/news/national-security/you-may-have-nothing-hide-you-still-have-something-fear#:~:text=The%20%E2%80%9Cnothing%20to%20hide%E2%80%9D%20argument,are%20not%20wrong%20or%20illegal https://www.aclu.org/news/national-security/you-may-have-not....
  - pugworthy 4y ago
    That's not really an answer beyond "Because FUD". FWIW, I've been an ACLU member for quite some time.
    - coldtea 4y ago
      FUD is a perfectly valid precaution where there's reason to be fear, uncertainty, and doubt. FUD is only a bad thing where there's no motive, precedent, and reason for those three - which is hardly the case here. Like, "This new roommate of yours might be a killer. Sure looks like one. And who can trust a man that doesn't have a Facebook page?", is bad FUD. But "Two ex-girfriends of this new roommate of yours have been found murdered in the woods, each a few years after they split. And I saw rope, duct tape, a set of hunting knives, plastic gloves, and a bottle of chloroform in the trunk of his car. Plus, when he got drunk he went on and on about how he likes this Dahmer tv-series. I think he might be a serial killer and you should be careful around him", is very reasonable FUD.

Time to get your own isolated grid huh? Maybe with solar and inverters?

by atoav 4y ago

Time to get your own isolated grid huh? Maybe with solar and inverters?

deleted 4y ago

[deleted]

ratww 4y ago

An on-line UPS like those used in datacenters or music studios is probably enough. They basically have rectifiers and inverters in them. Some of them have phase-locked loops to sync the output frequency with the mains, but probably won't stray as far from 50Hz (or 60Hz) as the mains themselves seem to do. If they do, unplugging the mains and using the battery is probably enough to get pure 50Hz back!

jsjohnst 4y ago
> An on-line UPS like those used in datacenters or music studios is probably enough. Only if you don’t have mains power anywhere near the recording device. You don’t need to be plugged into mains power to have it be present in a recording.
- ratww 4y ago
  True! And that applies for every case. Even if you have 100% isolated mains with solar or battery, you'll get 50hz from neighbours (especially apartments) and power lines close by. I remember having this issue when working in a recording studio during college, even when we switched to battery and turn the mains off, we'd still get hum in some guitars. Funny enough I was recently reading an interview with producer Michael Beinhorn and he mentioned having some "mystery EMF/RFI event" happening in New York around 1997, coming from a specific block, and he had to relocate a recording session to Los Angeles because of how strong it was interfering with the guitar amps and other equipment [1]. [1] https://gearspace.com/board/interviews/1385579-interview-michael-beinhorn.html#vw-head-80 https://gearspace.com/board/interviews/1385579-interview-mic...
  - jsjohnst 4y ago
    I really wish this story included which half block area it was strongest.
    - ratww 4y ago
      That would be very interesting to know! Especially considering the two studios he mentioned aren't exactly close to each other: https://goo.gl/maps/MLw3twvRi9GumYeX8 https://goo.gl/maps/MLw3twvRi9GumYeX8

s0rce 4y ago

You'd need to make sure there is no grid nearby. If you were completely off-grid and away from power lines or anything then you'd have no signal at the mains frequency. Certainly possible. Probably easier to just use a filter to mask the frequency component.

ris 4y ago

Probably better to run a decoy signal (or two) in the background with similar characteristics.

pugworthy 4y ago

To what end? What do you want to obfuscate by doing this?

coldtea 4y ago
https://www.aclu.org/news/national-security/you-may-have-nothing-hide-you-still-have-something-fear#:~:text=The%20%E2%80%9Cnothing%20to%20hide%E2%80%9D%20argument,are%20not%20wrong%20or%20illegal https://www.aclu.org/news/national-security/you-may-have-not....
- pugworthy 4y ago
  That's not really an answer beyond "Because FUD". FWIW, I've been an ACLU member for quite some time.
  - coldtea 4y ago
    FUD is a perfectly valid precaution where there's reason to be fear, uncertainty, and doubt. FUD is only a bad thing where there's no motive, precedent, and reason for those three - which is hardly the case here. Like, "This new roommate of yours might be a killer. Sure looks like one. And who can trust a man that doesn't have a Facebook page?", is bad FUD. But "Two ex-girfriends of this new roommate of yours have been found murdered in the woods, each a few years after they split. And I saw rope, duct tape, a set of hunting knives, plastic gloves, and a bottle of chloroform in the trunk of his car. Plus, when he got drunk he went on and on about how he likes this Dahmer tv-series. I think he might be a serial killer and you should be careful around him", is very reasonable FUD.