If you own or have used the Cushcraft MA5B in the past could you let me know
what the noise floor reading is/was and the rough height of your antenna?

I know that the noise floor will be different location to location but it
will give me some idea of what I should be looking at.

I have had mine up for a couple of years now and although the signals
increase 3-5 S points better than my Cobwebb and Dipole on receive the noise
floor has always been S7-8 on 14MHz. It is 0-1 S point on my other two
antennas. So any signal received on the MA5B less than S9+10db has a lot of
noise in there audio.
SWR is good on all 5 bands.