[Elecraft] Problem ... K2 Noise blanker is giving pulses

[Dave]

Robin

When the K2 is operating normally, there will be no pulses. These are only audible when making changes such as the DSP settings. The reason is the data lines are active 
when changing the settings and cause interference.

It's not a fault...

73 Dave, G4AON
K2 #1892
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Another day another challenge.

I have recently installed the 160m module and the 20 W ATU in my K2.
Now I discover the Noise Blanker gives  very strong pulse when I click Display 
and go into the DSP settings ... like on 14 Mhz is it most strong when I 
display "S1 nr nt". 
Pulses are at approximately 1 second interval and maybe one-fifth second in 
duration ... NB is supposed to remove the pulses not add them !!!
On std. rcv. there is no pulse noise.