[Elecraft] 160M module question

[Dave Benham]

I've been playing around re-aligning my K2 after adding the version 2
upgrade tonight.  Using Spectrogram, I noticed something I've suspected with
the 160M module I added quite a while back.  (I haven't operated any 160
with the K2, yet).   If I have no antenna on the K2, and am receiving just
noise, and set the peak of the waveform to -40db, then switch to 160M, the
waveform drops at least 5 db on the Spectrogram screen.  Is this normal?
The effect is much more pronounced with an antenna attached, but I don't
have a 160M antenna available where I'm doing this test so the resonance of
the antenna would be an additional factor.  If someone out there thinks I
might have a problem, what might it be?

Thanks.

73,
Dave  K8TRF