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fran604g wrote:
Thank you, Joe!

This serial number falls into the late (C250) transitional period, when the C250 exhibited the C19 style dataplate - still stamped with the C250 designation.

Did you happen to notice if the dataplate was the C19 style - Gold background with black lettering (white lettering if the black print is worn off) - like the one I have pictured below?


Best,
Fran

Fran, I edited the original post with an answer from the owner.

By the way, any idea what that bracket in the back was used for back in the day?

BwanaJoe wrote:

fran604g wrote:
Thank you, Joe!

This serial number falls into the late (C250) transitional period, when the C250 exhibited the C19 style dataplate - still stamped with the C250 designation.

Did you happen to notice if the dataplate was the C19 style - Gold background with black lettering (white lettering if the black print is worn off) - like the one I have pictured below?


Best,
Fran

Fran, I edited the original post with an answer from the owner.

By the way, any idea what that bracket in the back was used for back in the day?

Thanks, Joe!

The bracket was used to store the battery for the Electric Automatic Stop. It appears that the bracket was still installed after the E.A.S. was discontinued.

Best,
Fran

BwanaJoe wrote:From a machine I just looked at here locally:
Data plate is C19 style: "Same style but no color, white or black."
Motor plate is etched on top with M8506 left of center toward the top.

Wonderful, thanks!

I had a hunch...

Fran

fran604g wrote:

BwanaJoe wrote:

fran604g wrote:
Thank you, Joe!

This serial number falls into the late (C250) transitional period, when the C250 exhibited the C19 style dataplate - still stamped with the C250 designation.

Did you happen to notice if the dataplate was the C19 style - Gold background with black lettering (white lettering if the black print is worn off) - like the one I have pictured below?


Best,
Fran

Fran, I edited the original post with an answer from the owner.

By the way, any idea what that bracket in the back was used for back in the day?

Thanks, Joe!

The bracket was used to store the battery for the Electric Automatic Stop. It appears that the bracket was still installed after the E.A.S. was discontinued.

Best,
Fran

I wondered about that.

Was it true the reproducer should have a bent limit loop for the Duncan stop? This one did not (or at least it was not currently bent).

BwanaJoe wrote: Was it true the reproducer should have a bent limit loop for the Duncan stop? This one did not (or at least it was not currently bent).

Joe,

I don't know about the limit loop being altered one way or the other. The reproducer I have (from a c-19) has a bent limit loop. I've examined another from a C250, with an E.A.S. that has the same bent loop as mine.

I've read - posted here at TMF - that the limit PIN was extended for use with the E.A.S. (Electric Automatic Stop - aka "Duncan Stop" or "Duncan Brake") modified reproducer, but don't know if that's true. There are members here that have much more knowledge on the various reproducers used on the Diamond Disc Phonographs.

Three alterations that would have been on the modified reproducer (I've examined the Patent for my information, there may have been other alterations I haven't discovered yet):

1)The rear weight pivot cover was altered; a hole to receive the wire lead "metal tip" was in it.

2)The hinge block was altered; made of an electrical insulating material.

3) The limit loop (bottom half or so) was insulated with material.

This reproducer was designated in Edison literature as the "Type AA No.5 Diamond Disc Reproducer" in the instruction manual supplied with the C250 (form #1691-20M216.)

Best,
Fran

Fran

fran604g wrote: 3) The limit loop (bottom half or so) was insulated with material.
Fran

Fran,

I must plead mea culpa on this point. In one of our recent conversations, I mentioned the insulated limit loop, but I believe I was mistaken. It would be difficult and probably short-lived to bend a rubber tube around the 90-degree bend of the limit loop. Plus, the tubing would need to be split in order to add it after the unit was soldered together and plated.

In looking at my example, I believe the limit PIN had a short piece of rubber tubing applied only to the innermost area. This would insulate it from the limit loop when the reproducer was raised, but would still allow contact between the end of the pin and the loop when lowered into playing position. It also make sense from a manufacturing standpoint, and explains the need for a bent limit loop.

Again - sorry for my lapse...

George P.

phonogfp wrote:

fran604g wrote: 3) The limit loop (bottom half or so) was insulated with material.
Fran

Fran,

I must plead mea culpa on this point. In one of our recent conversations, I mentioned the insulated limit loop, but I believe I was mistaken. It would be difficult and probably short-lived to bend a rubber tube around the 90-degree bend of the limit loop. Plus, the tubing would need to be split in order to add it after the unit was soldered together and plated.

In looking at my example, I believe the limit PIN had a short piece of rubber tubing applied only to the innermost area. This would insulate it from the limit loop when the reproducer was raised, but would still allow contact between the end of the pin and the loop when lowered into playing position. It also make sense from a manufacturing standpoint, and explains the need for a bent limit loop.

Again - sorry for my lapse...

George P.

Hi George,

No apology necessary! We might both be correct. Time will tell.

I used the Edison (Shelly) Patent as the source of my information. The illustrations and text involved clearly indicate the loop as being insulated. Perhaps I should highlight the reference to the Patent in my post?

Certainly the insulation being on the PIN would make more sense - and be much easier to produce - but I haven't observed any reproducers with either the loop OR the pin with insulation still intact.

I'm loving this discussion, I hope we get other respondents with their observations!

Best,
Fran

Well, so much for my memory cells functioning correctly, I knew I'd read something recently.

In the December 2014 issue of The Antique Phonograph, Steve Medved reports that the limit loop was insulated. This makes sense, because I can't imagine how the pin being insulated could possibly work.

He also states the serial number for the Duncan Stop reproducer was preceded by the letters "EM," and a bent limit loop was used: "...you will find it [the bent limit loop] on regular reproducers so Edison either made them all that way for a while or used up the extra, or inter-mixed them as they [the bent limit loop] are found on regular reproducers."

Best,
Fran

fran604g wrote:
In the December 2014 issue of The Antique Phonograph, Steve Medved reports that the limit loop was insulated. This makes sense, because I can't imagine how the pin being insulated could possibly work.

In looking over my E.A.S. (often called the "Duncan Stop") reproducer, I find empirical evidence to back up the "insulated pin" theory. There's a mark on the pin that clearly shows where the rubber insulation must end (see photo below). I checked a number of other DD reproducers here, and none of them have this mark on the limit pin. After installing the piece of insulation, one can see how the insulated pin works in conjunction with the bent limit loop. While in playing position, the pin is raised and the rubber does not contact the limit loop. It's a far better option than trying to insulate the loop. And the "insulated pin" theory is borne out by the presence of the alignment mark on the pin itself, and the bent limit loop (why else would it be bent?).

George P.

EDIT: Changed "E.A.M." to "E.A.S." (Electric Automatic Stop)

phonogfp wrote:

fran604g wrote:
In the December 2014 issue of The Antique Phonograph, Steve Medved reports that the limit loop was insulated. This makes sense, because I can't imagine how the pin being insulated could possibly work.

In looking over my E.A.M. (often called the "Duncan Stop") reproducer, I find empirical evidence to back up the "insulated pin" theory. There's a mark on the pin that clearly shows where the rubber insulation must end (see photo below). I checked a number of other DD reproducers here, and none of them have this mark on the limit pin.

EASlimitpin.jpg

After installing the piece of insulation, one can see how the insulated pin works in conjunction with the bent limit loop. While in playing position, the pin is raised and the rubber does not contact the limit loop.

EAS1.jpg

EAS2.jpg

It's a far better option than trying to insulate the loop. And the "insulated pin" theory is borne out by the presence of the alignment mark on the pin itself, and the bent limit loop (why else would it be bent?).

George P.

Perfect, George!

Thank you! Your analysis explains both the bent loop AND the insulated pin!

Obviously the version shown in the patent (No. 1,395,017) was changed at some point during its development/production. Good to know!

I'll certainly note this in my research.

Fran