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Snagged my first Mercedes Dial on an AE 21 Candlestick off of eBay

Started by TelePlay, June 27, 2016, 09:37:29 PM

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TelePlay

Terry and Ken,

Thanks, I think I can replicate a reasonable facsimile.

Makes sense that they used both an insulating "gasket" and stand off washers given the construction of and the components on the terminal strip.



AE_Collector

I don't have the fiber washers but my 21 has been played with a lot. Shouldn't really be needed as the thin Bakelite insulates the back of the metal terminal from the medal and the terminal screws are centred to pass through the larger holes in the metal backplate without touching the metal. Using washers as well would allow for the thickness of the metal part of the terminals without warping the main Bakelite terminal strip at all.

Terry

TelePlay

After a bit of a restoration detour to get my top lift lantern done, I just finished the drilled perch which looked like this . . .



. . . and then this . . .



. . . and then this . . .



. . . and now this with its last coat of paint baked on. Turned out very nice. It looks better in real life, the camera is indeed unforgiving.

Overall, it took a lot of time but it was a great learning experience and as it will sit on my desk, I will know what went into it to get it there.

WEBellSystemChristian

Christian Petterson

"Whether you think you can or think you can't, you're right" -Henry Ford

Dennis Markham

Amazing repair, John!  Can't wait to see the project upon completion.

~Dennis

TelePlay

Started to work on a subset for the stick, an originally painted black AE Monophone ringer/subset wood box.

I found something that worked quite well for me when trying to refinish/restore the front door, and the back panel as well.

As manufactured long ago, it is a painted black, finger jointed, hard wood box. The front cover was quite dinged with dents, scratches, abrasions and quite a few areas where the black paint was chipped off showing the brown wood. I wanted to keep the character of the cover, all black but with the "as found" look. The rest of the box was in good shape except for the back which had thick, white wall paint on it on two lower edges/corners.

Started with the front cover first. Gently sanded the surface to get rid of edges and then went over it with 0000 steel wool soaked in Howard's Restore-a-Finish to clean the surface. Wiped off all residue after it dried. That left a clean, black painted, smooth surface with a lot of brown wood showing.

After trying a couple of things on scrap wood, I found a mixture that worked well, and fast. The intent was to make the brown wood black but keep the original color and surface character as found. Did this by mixing 1 teaspoon dark shellac, 1/2 teaspoon of ethyl alcohol to thin the shellac and 4 drops of black Aluminite Resin Dye. Aluminite dye, like shellac, is a resin so they did mix well. Mixed it up and applied it to the wood with a balled up cotton rag. Simple dipped the rag into the mixture and ran it over the wood with the grain.

The thinned mixture let me cover the entire front cover before it started to dry. Within a few minutes, it was dry enough to layer on another coat. I put move on the bare wood areas. The good areas got two coats, the chipped areas got 4 to 5 coats. This was all done in less than 20 minutes.

The paint on the back was thick and tough. Several applications of stripper didn't do much. Had to sand it off down to near bare wood. Once off, started with the Restore-a-Finish and ended up putting 5 coats on the bare wood areas and two on the rest of the piece to make the finish uniform.

Let each side dry overnight, cut the shiny surface down with 0000 steel wool and gave it a coat of Minwax paste wax. Buffed it out and took pictures.

So, I now have a nicely finish wood box that is near to original black. I assumed the sides were close to original in color and final finish so made the front and back match. Didn't do anything to the insides other than wipe the wood with a wet cloth. Have to finish the metal work and re-wire it to match my AE 21 (planning on adding a 101A per the AE booster circuit found on the TCI for AE 21 sticks. This ringer came with a 1 uF and 5 uF capacitor. Will post final pictures when I get the ringer back in.

Jack Ryan

Good work John.

Glad to see the cabinet being refurbished rather than "de-blacked" and varnished. I'm dot sure what the numbers were but you are lucky to have a finger jointed cabinet. Many were butt jointed and stapled.

Does the bell ring at 20Hz or are you going to modify/replace it?

Jack

TelePlay

Quote from: Jack Ryan on August 14, 2016, 08:08:30 PM
Does the bell ring at 20Hz or are you going to modify/replace it?

Thanks, Jack. It's becoming a major project but it's interesting and fun to sort of create an un-Frankenphone from parts.

Yes, the ringer does work at 20 Hz. I had a continuity issue with the coils and posted that in the "Troubleshooting and Repair" board, I thought a more appropriate place to discuss that interesting problem that was a bit difficult to "see." It's at this link:

http://www.classicrotaryphones.com/forum/index.php?topic=16564.0

It looks like this ringer box was used with a desk set and I don't have any idea of what would have been in the desk set to complement the ringer and it's two capacitors. It must have been a side tone set up unless their was an induction coil in the desk set.

I hope to fit a 101A in the box per AE wiring diagrams for an AE 21 stick subsets at the TCI site to get an anti-side tone stick unless I physically can't.

I was surprised to find a 5 uF cap in the box. I would assume the 1 uF was for the ringer (the diagram on the door is hard to read) and the 5 uF was the talk circuit. Maybe the other way around. The wiring diagrams show two caps but don't put a value on one of them. Any thoughts on this? Rewiring from scratch will begin in a month or so and will most likely have questions then.

I paid $20 for the box plus $15 shipping. No one else bid on it and looking at the eBay pictures might explain that. It came dirty but I think that combined with my once gutted, painted, ex-lamp phone AE 21 stick with a Mercedes dial will look very nice on my desk. It may not be 100% authentic but it will work.

Jack Ryan

Quote from: TelePlay on August 14, 2016, 09:14:04 PM
It looks like this ringer box was used with a desk set and I don't have any idea of what would have been in the desk set to complement the ringer and it's two capacitors. It must have been a side tone set up unless their was an induction coil in the desk set.

It may have been AST (see attachment)

Quote
I was surprised to find a 5 uF cap in the box. I would assume the 1 uF was for the ringer (the diagram on the door is hard to read) and the 5 uF was the talk circuit. Maybe the other way around. The wiring diagrams show two caps but don't put a value on one of them. Any thoughts on this? Rewiring from scratch will begin in a month or so and will most likely have questions then.

AE did use some fairly large talk capacitors and in your case, the value of the ringing capacitor was determined partly by the ringing frequency.

Jack

unbeldi

AE used 4 µF and 5 µF values for the talk capacitor in the circuits that used the later, i.e. WECo-style, AST circuit. I think it was introduced with the AE 40.

The earlier circuits, including the AE34 type circuit, used only one 1 µF capacitor for the metallic ringing circuit, or two 1 µF for grounded ringing.

I seem to read that the label on your subset states "For NO. 11 Monophone".  This probably explains the lack of induction coil, it was built into the handset, but I would have to search to see whether that ever required such a large capacitor.

Jack Ryan

Quote from: unbeldi on August 18, 2016, 08:45:59 AM
I seem to read that the label on your subset states "For NO. 11 Monophone".

So it does, I didn't see that - even though that is the circuit I posted.

The talk capacitor is 1uF but I can't see what the bell cap should be.

One of the capacitors in the unit is a replacement - which is which?

Jack

TelePlay

Work week over so time to catch up.

Yes, the door diagram state "Bell Box for No. 11 Auto Elec Monophone." The door diagram is not original as it was pasted over a larger diagram which is lost forever. Top diagram very tightly attached to bottom label.

In the image below, the diagram on the left is what is shown on the door (there is no value on the ringer cap, just MF). The right side shows the bell box wiring as received. Looks like the box was being used as an extension ringer with grounded (yellow) ringing. The only three wires screwed into the terminal strip were Green, Yellow and Red on terminals 4, 5 and 6 when counting from left to right.

As received, they were using the 1 uF (AE D6897 stanped 1 MF) capacitor (which tests out to 1.63 uF) for the ringer and the other cap (which has a paper label attached to it that darkened with age to unreadable but tests to 5 uF) was in the talk circuit, just the opposite of the AE diagram which has the 1 uF cap in the ringer circuit. Maybe someone just swapped out the cap connections when converting it to an extension ringer.

None of the wire colors stated on the door diagram match anything in the box.

Any thoughts?

TelePlay

Quote from: TelePlay on August 19, 2016, 11:27:27 PM
As received, they were using the light gray 1 uF (AE D6897 stamped 1 MF) capacitor (which tests out to 1.63 uF) for the ringer and the other dark brown to black cap (which has a paper label attached to it that darkened with age to unreadable but tests to 5 uF) was in the talk circuit, just the opposite of the AE diagram which has the 1 uF cap in the ringer circuit.

With a 30x loupe, I was able to make out what was printed on the dark brown, lower condenser. It reads

A.E. CO
CHICAGO
M.F. 2  TYPE D-6891
INSPECTED BY __________

but it tests to 5.0 uF. Anyone have the specs for a D-6891?

========================

Ran across the second image in my bell box file. Maybe this is the reason no one else wanted to buy the ringer. That's what it looked like when received.

unbeldi

Quote from: TelePlay on August 21, 2016, 03:49:45 PM
With a 30x loupe, I was able to make out what was printed on the dark brown, lower condenser. It reads

A.E. CO
CHICAGO
M.F. 2  TYPE D-6891
INSPECTED BY __________

but it tests to 5.0 uF. Anyone have the specs for a D-6891?

========================

Ran across the second image in my bell box file. Maybe this is the reason no one else wanted to buy the ringer. That's what it looked like when received.

The D-6891 is listed in Catalog No. 4055 (1934) with a capacity of 2 µF, and a size of 4.5" x 2" x 1".

TelePlay

After a few weekends of invention, the transmitter is finally done.

The lamp phone did not have a transmitter in the face plate and the face plate had threads for a Type 3 transmitter, IIRC the Type. Could not find a Type 3 transmitter but did find a complete SC transmitter with a Type 5, if I got that number right. Anyway, that is the 4 screw mount transmitter type so had to match the Type 5 transmitter to a Type 3 larger cup. Had to use the cup because the SC cut mount did not match to my perch. Needed one of those adapters mentioned on the forum every now and then.

So, starting with a 1/4" wide foot long brass bar, I bent it into a 2.9" diameter circle and soldered the ends together. The first brass bar I used was 0.135" thick (way too thick because I forgot to divide the difference by 2 when calculating what I needed - the fat circle one on the left ended up to be hand bending practice) so bent another circle out of 0.067 thick material (the one on the face plate) and after bending and bonding it to fit the face plate, cut the outside down until it fit nicely into the cup. The longer screws shown were used to check the 4 holes drilled in the brass adapter (would have been nice to buy one for $5 but no such luck).

After that, assembly of all the parts was quick and easy. Second image shows the parts front and back. Third image show partial assembly and the final product.

The transmitter tuned out quite well, at least to meet my expectations. Now, only one more thing to make before I can begin to assemble the stick and then make the internal wire harnesses for the subset and the stick and then connect the line to the subset to the phone. Piece of cake, right? Might get it done by Christmas, but which year, not sure yet.