Hi Ulf
The schematic of the Stromberg Carlson 636 is in Most Often Needed 1926-1938 Radio Diagrams by Beitman and Rider Vol. #1. The 636 is the same as the 635 except the detector grid circuit. Email you address and I will send you a copy if you are not able to obtain these books.
The schematic has 5 - 227 tubes, 1 - 171A and 1 -280. These were the old numbers from the 1920's. The newer numbers would be 27, 71A and 80 and are more easily obtainable.
Norm
Ulf Nilsson
Fyrskeppsv.60 1tr.
12154 Johanneshov
Sweden
Email scanreco@scanreco.se