I made a measurement of ambient noise on 144MHz this morning using the technique described at (Duffy 2009).
First step is to recheck the NF of the receiver. The TS2000 is getting a little tired, NF=8.3dB.
The technique calculates ambient noise from the variation in receiver output noise of a receiver of known Noise Figure with the insertion of a known input attenuator. The receiver output noise was measured using NFM (Duffy 2007) which allowed integration over 20s for high resolution measurement.