Some discussion here about band B operating at 1/2 frequency... perhaps it was designed that way, as it was observed on several units... makes no sense. How are you measuring frequency? The output of these cheap kit generators (like my Heathkit sg 8) is far from being a pure sine wave, which could fool a frequency counter.
http://antiqueradios.com/forums/viewtopic.php?t=153481
jr
is that a new new pot/switch, or did you unstick the old one?