Columbia Grafonola Favorite Reproducer

[chunnybh]

Hello all,
I am servicing a 1911-1912 Columbia Grafonola Favorite with two front doors.
It's all original but two of the three motor springs are broken. I've replaced all three and am now rebuilding the reproducer. My question, surly this should have a mica diaphragm?. The reproducer is marked patented 1905. I've checked for images of other Favorites online and was surprised to find that the ones I have found have the same black painted aluminum diaphragm. I am assuming this was a common upgrade offered by Columbia around 1925. Can anyone confirm my suspicions.
Thanks

[Inigo]

I believe I've seen this in Columbia catalogues or publicity, far before 1925. I believe it was a Columbia improvement over mica from earlier than the viva tonal era. I may be wrong, though... May be USA or UK Columbia...
Aha, here it is, Wilson & Webb 1929 modern gramophones and electrical reproducers, plate vii, Columbia sound boxes 1909-1928

I've also seen it in the image of the ELITE model in Baumbach Columbia Phonograph Companion vol II, the one pictured carries one of these soundboxes. I don't know if the aluminium diaphragm was there also in the subsequent models Concert Grand, which had a metal cover that didn't allow seeing the membrane.

[JerryVan]

My question, surly this should have a mica diaphragm?. The reproducer is marked patented 1905.

Not sure it was an upgrade. It's the proper diaphragm for that reproducer. As the to whether or not it's correct for a Favorite I can't say. I have a Columbia BII that has the same.

[chunnybh]

Thank you.
I've read "Modern Gramophones and Electrical Reproducers" so many times and still didn't notice this soundbox. The diaphragm is way ahead of it's time with the intricate ribbing and rings. The only downside seems to be the black paint on both sides of the diaphragm, which would have dampened it. Looks like the diaphragm was dipped in the thick paint. Odd how the later reproducers were still using mica. Must have been a cost thing.