The 628B is a six tube, two band, AC powered superheterodyne. The 628 chassis is identical electrically to the 638 and 5628 chassis. The 638 and 5628 differ only in the mechanical parts due to different cabinet styles.

The tubes used in this radio are:
6F5G   1^st. A-F Amplifier
6A8G   Oscillator-Modulator
6U7G   I-F Amplifier
6P5G   Detector, AVC
6K6G   Power Output
2W3     Rectifier