need to find ac 20v power supply for 3 legged phonemade by us robotics model no. cs1055 jack type usoc rj11c?

Answer 1

If you can't find it on eBay, you can probably have one built for you by any creative electronics person. An amateur radio operator (often called "ham" radio operator) almost always have the knowledge to build such a power supply. Otherwise, contact a TV repair shop if you can't find anyone. If the repair shop can't build it, the people shouldn't be in the repair business.