I have an Elonics 4000 USB receiver, and I-m trying to do somemeasurements on the digital television received power in my area. Everything works fine, except that the received power is never lower than -46 dB, even on channel which are not occupied. I was expecting to get values like -120 dB or something similar, instead in my measurements the lowest point in any portion of the spectrum is circa -46 dB.
Am I missing something?
Yes ... those are not absolute dBm values ... There is no calibration whatsoever so the '0dB' level doesn't mean 0 dBm at all ...
Cheers,
Sylvain