I have a simple RF section where I am trying to mix a 100Khz and a variable signal. Ranging around 98-102Khz. I need to build a mixer to get the difference of these frequencies. I wasn't sure what would be the best design or what to use? I was thinking about using Fets. I am new to this game so don't know a lot. The output will be fed to a low-pass filter to get rid of the addition of the two signals. I couldn't find any simple designs on the boards. Any help would be great.