Elecraft K3
SO2R K3, N3ZN ZN-5A, MicroHam MK2R+
K3 receiver audio measurements using Spectrogram:
Volume at 10 o'clock w/ only noise
Volume at 10 o'clock w/ signal injected from XG2 (S9)
For those with reduced or no hearing at 12 kHz, the beat notes are probably not an issue. However, with normal hearing in that range, there is a noticable difference in audio purity and can be rather annoying at times.
2010-06-22:
Elecraft is now including an audio LPF on the main DSP boards. Since getting the DSP modifications done, boths K3s are no longer exhibiting the above conditions and audio quality has greatly improved.