FRS should add feature to Flex6700 to Noise Nulling ability like the ANAN Radio's see HPSDR Phase N

MFJ has a similar unit. It requires two antennas. The big "IF" of the success of this technique is that one antenna should be subjected to a higher noise than the second antenna. This gives the unit enough information to discern between wanted and unwanted signals. If Flex were to implement this it might cause more problems than it solves in that meeting the conditions of subjecting one antenna to the noise source more  than another could be problematic and cause more complaints than praises.

Jim, K6QE

Hams have a tendency to over sell this technique. I had reasonable success using a vertical antenna as the noise antenna and a horizontal for the communications antenna. At times I could get a null as high as 10 dB, however, at other times, I could hardly get a null depending on how the noise propagated with time of day, weather, etc.

Jim, K6QE

I had sever noise problems coming from a close, coherent source. Not hash, wideband noise. It has to be close, and it has to have a determinate pattern for de-phasing to work. Tried several noise antennas (different polarization, different lengths...) and when you find the sweet spot, you can literally null out the noise and bring the band back. The offending noise here is gone from 15 and 17m, it was a neighbour with a small "plantation" at home with cheap, noisy chinese sodium light ballasts. A friendly visit with a portable spectrum analyzer fixed the problem, once he learned how he was broadcasting his wrong doings with a 599. It would be an incredible feature to implement on a Flex, specially for urban hams in noise infested locations (that's almost everywhere now). 

73 DE EA3HSO
AL

PS: 
Here's a link to a badly shot video of an ANC-4 demo at the shack.
Signals keep almost the same, noise dissapears.

https://www.youtube.com/watch?v=4EJXHpANxYY