[1000mp] Noise Blanker IMD

[George Cutsogeorge]

I have also run the IMD tests on a brand new Mark V Field.  The results are
similar to the results on the original MP.

It does not matter whether the NB switch is on or off.  If the level setting
is at minimum, there is no additional IMD.  So, if the menu is set to A=1
and B=1, there is no IMD added by the noise blanker.

With Toms mod installed, the A and B settings can be left anywhere and the
IMD problem goes away if the NB switch is set to off.  This is a bit more
convenient for people that regularly use the NB.

George, W2VJN