The Talking Machine Forum — For All Antique Phonographs & Recordings

In 1927 when Victor introduced the electrically amplified 10-51 automatic,they introduced a substantially larger horn driver with an electomagnet instead of the horse shoe magnet (the details are well documented in Look For The Dog in the rear of the book)To improve sales of the 9-40 and 8-60,some of these models were retrofitted with this driver.This required slight modifications to the amplifier in order to provide field excitation as would have been required in machines using the 104 type reproducer. It was original only to the 10-51,all other models using it were upgrades to existing models.

Oh, that’s super cool. Thanks! I’ll go Baumbach diving and see what I can learn.

When you finally get this thing in your hands and examine it, you will be amazed
at the construction and intricate pattern of the diaphragm..then you will realize
just what a lucky guy you are!!

Ok, I found the service notes in the back of LFTD and the thing appears to be quite cool. Are there any photos of them available?

oh, look: viewtopic.php?f=2&t=11771

Enjoy your journey with this one,Peter!

Thanks...

I am wondering if the machines that came west of the Rockies were mostly upgraded of the 6 I know of in the West 4 are the field coil driver ,and of course all the 10-51s have it the driver actually works to a bit lower than 100Hz ....mine does anyway .i was nervous going any lower cuz of the dreded POT METAL front cap assembly

Quick update on this monster; here is what has happened so far:

- Jerry picked it up in Portland for me, and trailered it down here to the SF Bay Area. He brought it to our doorstep on October 30, 2018.

- Jerry and I and a friend of mine strapped it onto an extremely robust two-wheel refrigerator dolly, rolled it up the driveway, and humped it up the four or five concrete front steps.

- We rested, and prepared to hump it over the 1” high threshold and into our tile-floored enclosed porch. Just get a rolling start and it’ll go up and over.

- It didn’t. It stopped dead at the threshold. I slipped, it fell on its side, and I fell on my butt.

- As it turned out, there was no damage to the 9-40. I wasn’t so lucky, doing a piledriver from 3’ straight down onto those tiles and sharply compressing my spinal column. Fractured “only” one vertebra, and did not get my legs or worse crushed by the 9-40, but make no mistake, it really really really hurt.

- Jerry kindly offered to take photos of me to document the event for this forum. I...declined.

- After a few months of recovery I was able to work on it. So...

- Obtained and installed a brass gear (made for restoration purposes in limited numbers, years ago) to replace the warped and crumbled air valve switch gear.

- Wayne Victrolamonkey researched and modified a set of four commercially available gears, for use in the antenna rotation gear train. Installed them.

- Had the Tomcat amplifier and power supply and capacitor bank rebuilt.

- Sent off the electrical pickup for rebuilding.

- Replaced the pickup’s wiring from tonearm to amp.

- Cleaned and lubricated the induction motor.

- Installed a Wyatt Markus rebuilt orthophonic reproducer.

- Obtained a full set of good vacuum tubes for the Radiola 28 and the Tomcat.

- Obtained a spare variable capacitor bank for the Radiola 28, to replace the warped original.

- Removed and rebuilt the pneumatic lid stays.

- Made up a new linecord, using modern cloth covered wire and reusing the original connectors.

- Verified continuity and correct range of resistance for the voice coil and field coil of the dynamic driver. I have high hopes for it, because the housing appears to have very little potmetalosis or deformation.

Next steps:

- Add protective fuses and grounding to the system.

- Install the rebuilt amplifier and test it with a known good input and a known good speaker (the system has a jack for connecting an external speaker).

- Install and verify proper operation of the rebuilt pickup.

- Connect and check operation of the dynamic driver.

- Replace the dynamic driver with a magnetic driver if needed.

- Follow service documentation to test and confirm operability of the Radiola 28, and repair as needed.

That would take it to its original operating capability. After that, I may take further steps, all of which will be fully reversible:

- Add Bluetooth input capability

- Add an original Victor 6” electrodynamic speaker (donor was a parted out 12-25), switchable from the Tomcat, in the record storage area

- Add an auxiliary input compatible with using an additional tonearm with an installed rebuilt Edison C-2 electrical pickup.

I will not:

- Replace the grille cloth. The grille is there but the cloth is completely gone. The horn is interesting to look at and is protected and obscured by the closed door when the machine is not in use.

- Turn it into a liquor cabinet (except for maybe a mini or two of Scotch conveniently stashed under the lid if I feel like it)

- Paint it white, make it distressed or shabby chic, or add International Orange highlights.

- Try to use my own body or any of its attached limbs to move the damn backbreaking Satanic Sound System ever ever again.

Man, what a "Satanic Sound System" monster! I look forward to your eventual video of it singing, Peter.

Tame the beast!

Wedge fractures aren't any fun, I hope you heal up as if it never occurred!

Cheers,
Fran