I disconnected everything except the DC power, and set Fil to 2.1Khz, and mode to USB. The static hiss is about the same (moderately loud) on all bands, including VHF and UHF. The pre-amp makes each band's static slightly louder.
The static noise looks the same across all bands using the JT65-HF waterfall.
Also, the static noise did not change as I tuned within each band.
On 14.076, the noise is at S7. When I turn on NB24%, the noise goes down to S3.
NR4 does not decrease the noise strength.
thanks again for any insight,