As anticipated, the noise is dominated by amplifier noise, with
possible substantial contributions from external interference.
Thermal noise is sufficiently small it is possibly unmeasurable in
practice.
The amplifier noise depends substantially on the quality of the op-amp
itself. The noise density from the amplifier varies from 30 to 150
#tex2html_wrap_inline1364# for reasonable op-amps. External
interference, even in a noisy lab environment typically remains below
50 #tex2html_wrap_inline1366#. Therefore, the total noise at the
receiver is between 30 #tex2html_wrap_inline1368# (low noise op-amp
and negligible interference) and 200 #tex2html_wrap_inline1370#
(generic op-amp and electrically noisy environment).