Hi all. I started a thread a while back about RF mixer design. I didn't know what to do or what design to choose. You guys laid some options for me and after some research and time I have finally decided that I will go for a double balanced, ring diode topology. Here is a schematic from google: So I think I get the general idea of the circuit and I am ready to simulate it and build it. I am wondering about one thing though, the two balun transformers... Is it possible to buy them already made? If so, how do I choose what I need? I would hate having to wind them myself as my hands do not allow me to undertake such delicate work. Thank you PF.