I have included a picture of what I would like to be able to make. I know that older phones operate on very specific MHz signals and that the newer ones are 2.4, or 5.8 GHz. I know there are scanners out there. But the purchase of one could be illegal, right? So why not make my own, to pick up the signal at my house. I can see where I would have to find the freq. of my phones here at home. The phones at my home are wireless, so I would think the voice signals are being sent through the base station out to the other landlines. Cell phones I imagine would be a more difficult target, I have seen where the freq. Number goes into the ten thousandths place, probably very hard to pinpoint. With the vast possibilities it would seem that this may be harder than I think, yes?