91–100 of 101 posts
Earlier quoted context omitted.
Ah, but if your neighbor's stereo is faintly audible in the distance while you record a screencast, your video will get taken down off Youtube very quickly.
Posting it publicly to YouTube is no longer for personal consumption. Do it with a private video, it won't be taken down.
Earlier quoted context omitted.
You can absolutely hook an antenna to a spec-an, but how do you calibrate the result? I can get a power measurement of mV or dBm at the instrument input, but that's not how the regs are written. They're written as field strength in free space (microvolts per meter), which as I understand it, either requires a calibrated field probe, or a calibrated antenna. I'm sure there's a way to perform such calibrations from fir…
You get a field strength the same way the pros do - from the antenna factors for your antenna and the cable loss. Look at a public FCC test report for an exposition of the method. DIY dipoles and even horns are not going to be very much different from ideal. Calibrated antennas are typically not more than a dB or two off ideal. Dipoles not even that unless they're broken. Horns and log-periodic antennas, enough that…
Solid gold search term right there, thank you!
> The primitive method for getting an antenna calibration is the three-antenna method.
More good stuff. Seriously, I hadn't gotten here and this is suddenly demystifying a lot of fundamentals.
Wave if you see me on the bunny hill! ;)
Earlier quoted context omitted.
Posting it publicly to YouTube is no longer for personal consumption. Do it with a private video, it won't be taken down.
That’s not true. Why do you say that? Content id takes down private videos too.
I guess they've since changed their policies.
From a copyright perspective there's no issue with uploading your own personal videos with copyrighted material in it to a site like YouTube so long as they're still private. I guess YouTube just assumes if you're uploading it there, you're going to eventually want to make it public. IMO they should just show the results of their scans to clue you into potential copyright claims but not actually do enforcement if the video isn't available publicly.
Note: an unlisted video is still a public video.
DSP engineer here:- the typical way to do this for better performance would be to do the FM modulation of each channel at a lower rate, say 100kHz, then use an FFT-based channeliser to mix each sub-band to the right carrier frequency and upsample in one step. That helps to break the n^2 problem mentioned in the article.
Earlier quoted context omitted.
You can absolutely hook an antenna to a spec-an, but how do you calibrate the result? I can get a power measurement of mV or dBm at the instrument input, but that's not how the regs are written. They're written as field strength in free space (microvolts per meter), which as I understand it, either requires a calibrated field probe, or a calibrated antenna. I'm sure there's a way to perform such calibrations from fir…
I have to admit that having a ham radio license that would be easy to take away is one reason why I wouldn't mess with anything questionable radio-wise. I wonder though if you could trust the published specs of a commercial FM transmitter to calibrate a power meter on it from a distance of a mile or so...
Even the douche canoe that intentionally interfered with firefighting efforts recently only got a hefty fine. He still has his license.
Ham radio licenses are granted by the FCC with the understanding that the the license-holders intend to experiment and explore radio technology. And further understanding that while licensees are expected to adhere to all of the rules, mistakes will sometimes be made. Hams are therefore given wide latitude in terms of self-policing and forgiveness for accidentally or unknowingly breaking them from time to time.
With some filtering on the output to knock down harmonics and aliasing noise, and as long as the power output is low enough, this could actually be legal in the US. IANAL, etc, but this is my understanding: It's actually ridiculously tricky to measure transmitter power output in the terms that the FCC regs are written in, but the rule of thumb is that, given the receiver sensitivity of a typical radio, if you lose th…
Basically if anyone receives it that wasn't expecting to it's illegal. That is at the core of the FCC rules in the US, you can't interfere with the lawful use of the band, nor can you cause "interference" on unused bands. That said, the process for prosecuting you is long and somewhat convoluted as they have to file a report, then the FCC will confirm the report, Etc. But this kind of project (and a similar I saw tha…
Are there any countries where that isn't illegal?
Earlier quoted context omitted.
Basically if anyone receives it that wasn't expecting to it's illegal. That is at the core of the FCC rules in the US, you can't interfere with the lawful use of the band, nor can you cause "interference" on unused bands. That said, the process for prosecuting you is long and somewhat convoluted as they have to file a report, then the FCC will confirm the report, Etc. But this kind of project (and a similar I saw tha…
> if anyone receives it that wasn't expecting to it's illegal. Are there any countries where that isn't illegal?