sentences:  The SP-400 Super Pros were very similar to the SP-200's with the differences being mainly cosmetic.They were only made from 1946 to 1948 and had outboard power supplies like the earlier Super Pros.There were two of them, the SP-400-X which tuned from .54 to 30 MHz, and the SP-400-SX which tuned from 1.25 -40 MHz.