Author Topic: Fatboy...kinda  (Read 1300 times)

Offline cloyd

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Fatboy...kinda
« on: December 01, 2016, 03:41:07 PM »
Hello everyone!  Thank you for reading.

I finally bought an SC 1212 "Fatboy" and I would love to get an analysis of what it is I actually have.  The dial is certainly wrong, it may have a frequency ringer, the transmitter element is stuck tight in the handset apparently considering how bent it is and I was even suspecting that the cradle might be a reproduction.  Why is there an  additional connection board in there?

Let me know what you think.  I'm a big girl; I can take it.

Thank you,

Tina
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

Offline Jim Stettler

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Re: Fatboy...kinda
« Reply #1 on: December 01, 2016, 06:47:41 PM »
50 hz frequency ringer and it is missing the insect screen. The screen material is like the screen used on AE40's.


JMO,
Jim S.
You live, You learn,
You die, you forget it all.

Offline cloyd

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Re: Fatboy...kinda
« Reply #2 on: December 14, 2016, 01:26:24 PM »
The SC 1212 Fatboy is coming together nicely.  It looks good and it rings but I can't get it to do anything else.  I have gone over the schematics many times and checked the continuity of the cables.  Everything was good except the yellow line cable so you will see a bright yellow wire in the pictures filling its role.

If anyone can spot my error I would really appreciate it.  I have included lots of pictures with angles to try to see the direction that cables go.  If anyone has a neatly wired 1212 that they could post a picture for, I would like to clean up what I have done.  I just tried to route them so they wouldn't interfere with the other moving bits inside.

Thank you!

Tina Loyd
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

Offline cloyd

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Re: Fatboy...kinda
« Reply #3 on: December 14, 2016, 01:30:48 PM »
This is what I started with.  It was wired with a connection board for a manual model even though when I bought it it had a newer rotary dial that I replaced with an AE type 24.
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

Offline Slal

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Re: Fatboy...kinda
« Reply #4 on: December 14, 2016, 06:01:18 PM »
Like the 'dressing' on newer wires for ringer.  Many would just cram them in there.  ; )

24 dial a good choice.  Don't have docs right in front of me, but depending on age--  think the 24A36 was introduced in 1936 if memory serves correct.

Anyway, nice find and good job converting it!

Best

--Bruce

Offline cloyd

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Re: Fatboy...kinda
« Reply #5 on: December 14, 2016, 06:32:44 PM »
24 dial a good choice.  Don't have docs right in front of me, but depending on age--  think the 24A36 was introduced in 1936 if memory serves correct.
Anyway, nice find and good job converting it!
Best
--Bruce

Thanks Bruce!  How can you tell if an AE dial is a 24A36?  Can you tell on my dial?  Since AE doesn't put dates on their phones, what is your guess for the age of my phone?  It came with the older style handset that I love.

Tina
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

Offline cloyd

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Re: Fatboy...kinda
« Reply #6 on: December 15, 2016, 01:13:34 PM »
I still can't get the wiring done correctly in this phone.  It had a dial tone before I added a dial and a straight line ringer.  It rings now but no dial tone or electrical noise at all.  I have attached an image of the schematic that I am using and the area that I am unsure about is indicated in the purple square.  How should the red lines from A and D that join the other red line look like in the phone?

I tried making a connection between A and E and then bridged D to A.   :-\

One more question, the Red White label in the center of the diagram is also confusing.  What is that all about?

Thank you for the help.

Tina
« Last Edit: December 15, 2016, 01:19:24 PM by cloyd »
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

unbeldi

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Re: Fatboy...kinda
« Reply #7 on: December 15, 2016, 01:23:17 PM »
Tina, it should be wired like this.

From the original wiring with the terminal strip in the dial-less configuration, the green, red, white, and brown wires attach to the dial as shown in the second diagram.

Of course, the first diagram leaves out some wires, to the induction coil and others...
« Last Edit: December 15, 2016, 01:25:55 PM by unbeldi »

unbeldi

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Re: Fatboy...kinda
« Reply #8 on: December 15, 2016, 01:38:40 PM »
Here is a complete circuit diagram for the 1212, drawn as per 1942 catalog, using the standard AE dial with three off-normal springs.

The catalog drawings are impossible to actually understand, this should illustrate the principle much clearer.  The circuit is somewhat different than the later Stromberg-Carlson AST circuit, which was more like the WECo arrangement.

« Last Edit: December 15, 2016, 01:45:30 PM by unbeldi »

Offline cloyd

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Re: Fatboy...kinda
« Reply #9 on: December 15, 2016, 04:04:50 PM »
The catalog drawings are impossible to actually understand, this should illustrate the principle much clearer.  The circuit is somewhat different than the later Stromberg-Carlson AST circuit, which was more like the WECo arrangement.
Unbeldi, you are absolutely right when you say that the catalog drawings are impossible to understand!  While  you were busy making your colored diagram, I made one as well.  I spent time on it so I am going to post it.  I am excited to get home and try to get it to work.

Thank you so much!

Tina
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

unbeldi

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Re: Fatboy...kinda
« Reply #10 on: December 15, 2016, 04:14:41 PM »
Does your induction coil have any numbers printed on it ?
All I have ever seen is the part number 23124, it is in the catalog and I think I have seen that also printed on top of the induction itself. Yours appears to be blank at that spot. I believe Ralph Meyer reports it as No. 45, but his book shows different values for the windings than the catalog does.

Offline cloyd

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Re: Fatboy...kinda
« Reply #11 on: December 15, 2016, 04:59:15 PM »
No, the induction coil doesn't have any numbers but I will look again.

Another question that I have is about the yellow line cord connecting to H.  In your diagram, you didn't highlight it as yellow and I am wondering if it is not needed.  If not, why is that?  I thought grounding electrical equipment was a safety measure.  If I connect the yellow to H, will it make a difference one way or the other?

Thank you,

Tina
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

unbeldi

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Re: Fatboy...kinda
« Reply #12 on: December 15, 2016, 05:12:35 PM »
No, the induction coil doesn't have any numbers but I will look again.

Another question that I have is about the yellow line cord connecting to H.  In your diagram, you didn't highlight it as yellow and I am wondering if it is not needed.  If not, why is that?  I thought grounding electrical equipment was a safety measure.  If I connect the yellow to H, will it make a difference one way or the other?

Thank you,

Tina

The yellow wire is not needed at all.  Since this is not an electrical appliance, i.e. not using grid electricity, there is no need for a ground connection as protector.  The H terminal is not connected to anything anyways.   But of course, there is a need for protection against lighting strikes  into telephone transmission lines.  The protection against this, however, is implemented outside, just before the telephone lines enters a residence. Essentially it directs the excess current into a ground wire across a carbon block or some other more modern device.

The third, yellow wire in the line cord was used for grounded ringing in which the A.C. ringing current is sent to the subscriber on either red or green, while the return path is Earth ground to the central office.  This hasn't been in use anymore for decades, and was one of the methods for selective ringing on party lines.   On a two-party line  one party is rung from tip (green) to ground, and the other from ring (red) to ground, so that the two sets ring completely independently.

Today everyone gets an individual service line, and ringing happens between green and red only.

Thanks for checking numbers. The mystery continues...

PS: well it's not really a mystery, the forum actually provides some answers.   Indeed I have found the two kinds of induction coils in pictures here.
* No. 23124 as shown in the catalog
* No. 45-A
The question is, are they different ?

« Last Edit: December 16, 2016, 08:40:08 AM by unbeldi »

Offline Slal

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Re: Fatboy...kinda
« Reply #13 on: December 15, 2016, 06:34:45 PM »
Thanks Bruce!  How can you tell if an AE dial is a 24A36?  Can you tell on my dial?  Since AE doesn't put dates on their phones, what is your guess for the age of my phone?  It came with the older style handset that I love.

Tina

Quite welcome, although vagaries of AE dials probably not as important as solving circuit right now.  ; )

To answer question though, can't really tell from the bottom of dial.  Yours has "Automatic Electric" in an oval, which is "early" before they changed their logo.

Only sure fire way to tell, is to remove finger wheel and number plate.  Find the pawl and see if there's a bit of wire on it.

From Tech Bulletin page 528, August, 1949, p. 5  "Note the spring in the center of the pawl which reduces the noise of the pawl clicking over the ratchet teeth." 

The PDF file should be available at TCI, or it was a couple years ago.  ; )

Here at CRPF, member "GG" posted a a good overview and explanation about AE dials here:

http://www.classicrotaryphones.com/forum/index.php?topic=5867.msg70490#msg70490