sallen key on breadboard

[denver56]

Hello! I am releasing on breadboard a high pass filter sallen key + low pass filter SK + passive low pass filter on a breadboard. Acquiring the out signla with labview I had a 3 khz noise that increase too much the gain. Look ak the pics / video. Any idea?
On the video I increase the 1 mv input signal frequency starting from 660 Hz.
Thank youView attachment 20121030_1634_00.zip

 

[FvM]

I don't think, that the video explains anything without knowing what the input and output signals are. Where do you see 3 kHz noise"?.

 

[denver56]

the two single stadium separately kept have gain = 10 but when they are linked together I have more than 10*10 gain in bandwidth (almost 200..) Any idea ?