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Re: Path loss and signal calc...



Lisa R. McCarty wrote:
> 
> > >  How can one relate this mesurment with  signal strengths
> > > that are expressed in dbm or decibles as they relate to microvolts?
> > > That is, how does a signal that is said to be -140dbm relate to
> > > the measument of .2uv at (10db s+n/n)
> >
> > The .2 uv is into a 50 ohm load.  Solve for power and then 10 times
> > the log of the power is the dbm.  The answer is -151 dbm. (I think).
> > Remember this is for a certain bandwidth, narrow the bandwidth and
> > the figure gets better.
> 
> Oops, more like -120 dbm, -150 would be decibels below one watt or
> dbw.
> 
> Mike, KB8YHV/KH2

Or convert the .2 uV to dbuV      ie: 20 log .2 = -13.98
Then simply add it to -107 dbuV (dbm relation)   
                               
Hence:  -107 + (-13.98) = 120.97 dbm

--db-- (AA2GF)



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