The project was to see if noise emitting from the laptop would cancel. It did. After many tests, and wacky techniques, the low pass filter build was the most effective. CB radios and Ham radios next to a terminal in a shack often causes horrendous noise or Interference. The low pass filter circuit eliminates most of the noise, and will produce a quieter station setup. I have included 2 photos, one of the 1st stages of the build, and the schematic diagram. The circuit consists of a LM741 op amp, resistors of 1k ohm, two 10k ohm, and 4.7k ohm, and a 1 nano farad capacitor. Plus/Minus 12 VDC. At any rate the build was working at more than minimal level. 73. KI6FTU.