5 Mar
2020
5 Mar
'20
8:22 p.m.
On 2020-03-05 10:38, Zach Metzinger via AMSAT-BB wrote:
-174 dBm + log(3000 Hz / 1 Hz) ~= -170 dBm
This is the thermal noise floor in a 3 kHz bandwidth from a noise source at 290 Kelvin (62 deg F).
Thanks go to WB4APR for spotting my math error; I added Bels to deciBels. At the time, I thought "that seems a bit low", but never went back to check my work. :-)
The correct answer is:
-174 dBm + 10*log(3000 Hz / 1 Hz) ~= -139 dBm
--- Zach N0ZGO