"chuck" wrote in message
ink.net...
Hello Gary,

You've posted some interesting information.

I wondered about the inherent non-linearities and, of course, the
deviation at which the SINADs were measured is not known, either.

The SINAD is measured with a single tone and the measured audio output is
bandwidth limited with a filter with strict specifications, commonly known
as as CCITT or P53 filter.

So the
question boils down to whether modern VHF receivers for marine use are
likely to have noticeably different sensitivity performance.

As you know, SINAD is a measure of "useful sensitivity" and the noise
plus distortion part of SINAD (rather than the signal part) is what is
probably affecting the differences in VHF receiver SINAD measurement.

Taking the issue into the realm of the real world, Icom quotes the
following for their IC-F4GT/GS radios:

0.3 microvolts for 12 dB SINAD
0.79 microvolts for 20 dB SINAD

The TK3160E UHF Transceiver reports similar results:

0.25 microvolts for 12 dB SINAD
0.63 microvolts for 20 dB SINAD

These both work out to Meindert's results very closely. So we know that
by assuming linearity, we are not necessarily wildly out of the ballpark.

Indeed. 0.63 vs 0.uV is 8dB, as well as 0.25 vs 0.63 mV.

Meindert