It would definitely date from the
late 1920s, probably around 1927/1928.
The Panatrope was actually Brunswick's name for their all electrical (tube amplified/loudspeaker equipped) phonograph, designed to play the newly introduced electrically recorded records, which hit the market in late 1925. Since the other major phonograph manufacturers were offering lines of acoustic phonographs designed to play these records--such as Victor's Orthophonic Victrola and Columbia's Viva Tonal Phonograph--Brunswick got on the bandwagon and produced their own all acoustic models, adding the word "Exponential" to the Panatrope brand name.
If you haven't seen it, this is a good primer on Brunswick phonographs and records --
http://www.gracyk.com/brunswick.shtmlWhile they are high quality, in terms of their construction, the exponential horn Panatropes did not quite have the sound quality of their rivals, especially Victor products. (For starters, their horns are not really exponential in shape.) Still, when fully restored, they provide a room filling sound, with a good mid-range and treble, though somewhat lacking in bass performance.
There are a number of youtube videos showcasing Panatrope exponential horn models, such as --
http://www.youtube.com/watch?v=tAjMFwxz ... re=related(For comparison, here's one showing Brunswick's all electrical Panatrope --
http://www.youtube.com/watch?v=yEplbvrxI64 )
I noticed you said the crank and grille cloth was missing. You might want to check with some of the shops specializing in antique phonograph repair to see if they might have something that will fit.
Here are a few to check out, if you're interested --
Victrola Repair Service --
http://www.victrolarepairservice.com/The Antique Phonograph Supply Company --
http://www.antiquephono.com/Shenandoah Antique Phonograph Repair --
http://www.shenandoahrestoration.com/phono.htmlJohn Lewis's Mechanical Antiques Repair --
http://www.antiquephonograph.com/HTH,
Joe