3 ms·
So what makes the radio waves magically drop off the face of the earth after .5m? And who allows 40 dBm (much more if we're talking at .5m distance) in an ISM b
by revelation 9y ago
So what makes the radio waves magically drop off the face of the earth after .5m? And who allows 40 dBm (much more if we're talking at .5m distance) in an ISM band?
I mean, that test report is making a lot of assumptions and setup constraints that are now magically not present in the video..
- deepspace 9y agoYes, I have been trying (unsuccessfully) to get my head around how the test setup would translate into a practical application. And that the certification appears to violate the FCC's own 30dBm power limit in the 900MHz ISM band. Very strange.
- phasetransition 9y agoThe ISM field strength levels here are defined in 47 Part 18.305. they are measured in an anechoic chamber and inverse square law scaled to the field strength at the stated distance. Source: I used to work with RF lighting devices, which need to meet the levels of 18.305(c), and were usually tested the same way in pre-compliance before final OATS testing.