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Every radio receiver has a minimum internal
noise level. Circuit design as well as thermal and electrical noise of the
components cause this and that level us usually referred to as the "noise
figure" of the receiver. When connected to an antenna the receiver will also
receive a variety of atmospheric and man made noises. "Noise floor" refers to
the signal level of the noise from any of the above sources. The noise floor
can, and often does, vary with time of day, weather conditions, and other radio
activity in the area. Does anyone remember how to convert noise figure (usually
expressed in db) to signal level (usually expressed in dbm)?
In order to receive useful information from a
distant transmitter your received signal has to be at some level above the noise
floor or noise level. The difference between the noise and the intended signal
is called the SNR or Signal to Noise Ratio. Useful radio communication requires
enough SNR to discern the information being transmitted from the
noise.
The Orinoco client manager that comes with their
cards will display noise level, signal level and SNR. Smartbridges reports RSSI
and Signal quality and I have never figured out how they relate to real world
numbers.
John
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Title: RE: [smartBridges] Sector antenna range vs omni
- Re: [smartBridges] Sector ante... Dennis Burgess
- RE: [smartBridges] Sector ante... Nish Park
- Re: [smartBridges] Sector ante... Eje Gustafsson
- Re: [smartBridges] Sector ante... Eje Gustafsson
- Re: [smartBridges] Sector ante... Eje Gustafsson
- RE: [smartBridges] Sector ante... Kevin Summers
- Re: [smartBridges] Sector antenna ... Eje Gustafsson
- RE: [smartBridges] Sector antenna range vs omni Jeremy Oswalt
- Re: [smartBridges] Sector antenna range vs omni Dennis Burgess
- RE: [smartBridges] Sector antenna range vs omni phantam
- Re: [smartBridges] Sector antenna range vs omni Stuart Pierce
- RE: [smartBridges] Sector antenna range vs omni Gino A. Villarini
- RE: [smartBridges] Sector antenna range vs omni Kevin Summers
- Re: [smartBridges] Sector antenna range vs omni Tim Harris
- RE: [smartBridges] Sector antenna range vs ... Joe Kelley
- RE: [smartBridges] Sector antenna range vs ... Colorado Wisp
- Re: [smartBridges] Sector antenna range... Lewis Watson
- Re: [smartBridges] Sector antenna range... Dennis Burgess
