Well the quad bilateral switch then sounds better than I thought if it is analog with digital controls. And it is popular in use.
Mentioning the IP3 in that last post in regard to the SA612 Gilbert Cells. I read a few articles perhaps the best at Wikipedia. I was wondering if there is any software that allows you to explore the IP3 responses and get an idea about the math? I found one MS Dos software and it doesn't explain anything really. And it doesn't do the big long equations either. Dan
