So how do the ones with a single button for volume and channel work ? Did you have to cycle all the way around or were they rocker switches ?

http://collectibles.shop.ebay.com/Radio-Phonograph-TV-Phone-/29832/i.html?_catref=1&_fln=1&_ssn=mjjr1956&_trksid=p3911.c0.m282

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