Columbus had several different model 18 variants - these were a 1936 dual wave 6-valve (plus eye on some models) set.
I.F. Frequency: 456kc/s
Chassis Notes: Model 18 chassis, found in tabletop cabinets, often with a vibrator power supply, or tombstone as mains only. Dual wave. Radiomuseum has a tombstone without magic eye, and the schematic does not show one. Production serial numbers have been noted in both 1936 and 1937.