Recent increase of noise floor on higher frequencies

Lately, maybe within the last week or so I've noticed an increase of the noise floor from 15-20Mhz upwards. There was always lower amounts of noise up there previously. Initially I thought it was antenna introduced until I started investigating. I ended up disconnecting the antenna at the kiwi and of course the signal dropped but noise remained on those higher frequencies. So I substituted the well filtered SMPS for a Lithium Phosphate battery and linear regulator with no difference (some change on LW frequencies though). The network has a ceramic mix 31 filter on the Cat6 cable and the router has been rebooted etc. I also tried disconnecting the GPS antenna but I can't find the source of the noise. i haven't tried a direct link from the Kiwi to a laptop (not sure how to do this) but it's mystery at this stage. Not sure if the noise is being generated inside the Kiwi or it's picking up something external? Any ideas?