[Elecraft] XG-1 MDS Calculation

[Bill Tippett]

At 03:33 PM 5/17/04, NC6M wrote:
>The definition of MDS is a signal that is equal in power to the noise
>present in the channel.  When the s+n/n ratio is 3 dB this condition is met
>with the signal and the noise each making an equal contribution to the total
>power.  In the case of a measurement made with the XG1, the s+n/n ratio is
>much greater than 3 dB and the contribution of noise to the total power
>measured in the channel is negligible, therefore the  MDS is simply equal
>to -107dBm - s+n/n.

         Thanks Bob, but then I'm wondering about the apparent discrepancy
between measurements with my XG-1 and ARRL's measurements.  I assume
I should still normalize any actual BW difference (to the 500 Hz standard).  I
thought I had the difference nicely explained with the additional 3 dB in
the MDS definition, but your comment leaves me wondering why I'm now
measuring MDS 3 dB lower than ARRL's measurement.  Any ideas?  Could it
be due to using an average-responding instead of RMS-responding meter?

                                 73,  Bill  W4ZV