Hi Looking at my K2 the encoder A and B lines have ~.5 ms pulses every 1.5 ms switching +5 to ground. If you rotate the encoder the pulses will go away and the A or B line goes to +5 dc and then the pulses return as you rotate the encoder. Don Brown KD5NDB K2 #1808,#2174,#2153 sold - number 4 on order K1 #1000,#542 for sale