[codefox1]

Seen this before, and yeah, makes no intuitive sense. Selectively shorting out the antenna does lower volume, as does starving the filaments in the front end. You must realize that there were a lot of patent wars and snake oil battery saver salesmen in the olden days.

But there are still enough specimens around to study, if for no other reason than to guess what was going through the minds of the desiners, draftsmen, bean counters, and marketing people of the era, not to mention the patent attorneys, suppliers, pols and financiers.

Nothing has changed. SSDD