4 ms·
0Hz is definitionally the lower limit of information-carrying frequencies (presumably this is not actually capable of detecting anything between zero and 1Hz -
by fwlr 4y ago
0Hz is definitionally the lower limit of information-carrying frequencies (presumably this is not actually capable of detecting anything between zero and 1Hz - not that there’s much of interest in being broadcast in the micro-, nano-, or pico-hertz range anyway), and 20GHz is well into the realm of “millimeter-wave” broadcast frequencies. That’s ten orders of magnitude, and you only have about 1 order of magnitude more before you start seeing complete atmospheric attenuation on the scale of meters. So their claim that this is a genuinely general-purpose receiver is pretty much true, surprising as that may be.
- danbruc 4y agoFor $20k you can have one, too, 100 kHZ - 20 GHz. [1] [1] https://signalhound.com/products/sm200c-20-ghz-real-time-spectrum-analyzer-with-10gbe/ https://signalhound.com/products/sm200c-20-ghz-real-time-spe...
- jonathanstrange 4y agoI'm curious: Aren't these kind of devices illegal in most jurisdictions? Who uses them anyway?
- jacquesm 4y agoOf course not. Anybody doing serious RF engineering has a spectrum analyzer or access to one. For that kind of work a spectrum analyzer is more desirable than an oscilloscope.
- Cthulhu_ 4y agoReceivers, probably not; broadcasters may get the FCC breathing down your neck if you take the piss though. And there's probably specific laws about breaking encryption, e.g. law enforcement communications.
- fsh 4y agoRF receivers were restricted in some jurisdictions. However, a 30€ SDR stick can receive pretty much any unencrypted voice transmission which makes these rules impossible to enforce.
- jimmySixDOF 4y agoInteresting they have a 10Gb interface with their own proprietary UDP SAR encapsulation. Pseudowires was a way to mux payloads like this onto the network but make a lot more sense for them to do it especially at that framerate. It could give you a pretty wide sample zone if you had a few of these and a lot of fiber.
- deleted 4y ago[deleted]
- dvh 4y agoDoes 0Hz wave even fit inside our universe?
- jacquesm 4y agoTechnically it has infinite wavelength.
- dan_hawkins 4y agoUniverse is infinite so technically it fits.
- maze-le 4y ago0Hz is a constant value -- 0Hz means the electromagnetic field does not oscillate. The lowest frequency concievable would be something like ~2.2978 10E−18 Hz -- one period every 13.8 billion years. [0]: https://en.wikipedia.org/wiki/Orders_of_magnitude_(frequency) https://en.wikipedia.org/wiki/Orders_of_magnitude_(frequency...
- jacquesm 4y agoIn a way the expansion of the universe is one half of a giant wave.
- totetsu 4y agocan a 0Hz wave move through space? or is it just a static field..
- maze-le 4y agoYou can think of it as the "static" component of a variable field. Frequencies above 0 Hz oscillate, and the 0 Hz component keeps a static value.
- KyleBerezin 4y agoI'd love to know the DC offset of the universe