Novice restoring an SC1443; wiring question

[cwbristow]

I'm restoring a Stromberg Carlson model 1443 for my father-in-law.

I have a wiring question. I've wired in a regular 4-wire RG11 cord in order to be able to plug it in a phone jack, and see if it works. I have dial tone, dial capability, and the mic works, but no ringer. I have something wrong I guess. I only connected the green, yellow, and red like the old wiring was and left the black unconnected. I only rewired the line-in side, not the other/handset side. Can anyone send some advice my way?

Below I've attached before and after pics of what was done.
1- old line-in wiring
2- new line in wiring
3- untouched handset side



Old line-in




New line-in




handset side

[unbeldi]

Welcome!

During the previous lifetime of this phone most telephone lines used grounded ringing. The ringing voltage was applied to either the red or the green lead, and the return was via an earth-ground connection on the yellow lead.  Today ringing is strictly applied between ring and tip, or red and green.
So to make this old telephone ring, you need to short the yellow wire to either green or red.  Try green first, because that was the standard for individual line service, whereas it could be either green or red when the set was installed on a party line.

The other potential problem may be that the ringer is not a standard, so called straight-line ringer, that responds to 20 Hz ringing frequency, but to a higher frequency, potentially up to 66 Hz.  If you post a picture of the ringer we can decide what kind it is.

PS: I think these sets may have had an optional metal strap on either the G (yellow) terminal or the L2 (green) terminal, which could be installed or removed, depending on need.  If present, simply install it across G and L2.

What is the complete code stamped on the bottom of the phone.    1443 ?   any letters?

The ringer should actually have a code stamped on the mounting plate between the screws that hold it to the telephone base,   something like  72X-NN,   were X= a capital letter, and NN=frequency

[cwbristow]

It actually is stamped 1543... So I may be wrong.
This was his parents phone and it has an exterior ringer with it, but it is not attached.
I'm just trying to get the phone itself cleaned up and working.

[TelePlay]

That appears to be a 50 Hz frequency ringer. Can you open up the external ringer box and post photos of the ringer and whatever else is inside the box?

[unbeldi]

It actually is stamped 1543... So I may be wrong.
This was his parents phone and it has an exterior ringer with it, but it is not attached.
I'm just trying to get the phone itself cleaned up and working.

Alright, I was getting suspicious actually after I posted, when I looked at my pictures of a 1443.  The handset side network connections have different colors.

The 1543 is the successor model after the 1443.  The 1443 was a somewhat short-lived type, that was Stromberg-Carlsson's first step of modernizing the 1243 and making it look a little like the WECo 500.  The 1543 was made starting about 1955 or 1956, and used similar components and styling initially as the 1443, but was changed considerably later on, including the upgrade to the 500-style self-compensating network.

Yours looks like an early version of the 1543.

From the model number you quoted,  2-1543WG, we see that the phone indeed has a frequency-selective ringer, a 50 Hz ringer.  This is encoded in the letter G, and is also printed underneath as 50~.  This means this phone will not be able to ring on modern lines. We don't even have to fiddle with the connections.  If you have a VoIP service, some adapters can actually be configured to ring at that frequency, but not many.

The prefix 2– means that the hookswitch is special. It has a two-step function so that when the handset is lifted one can only listen in on the line.  Pushing a plate or button in the cradle, connects the transmitters and dial to the line as well.  This was used on party lines so people would not disturb any calls already in progress.

The letter W designates that your phone has the compensating network design already, which is also reflected in the red ink stamp on the network:  210640.

The extra ringer box may be your savior for ringing, but we have to open it to determine the type of ringer installed. It may or may not have been part of the telephone's installation.

[cwbristow]

Here's the guts to the exterior ringer.

[unbeldi]

Here's the guts to the exterior ringer.

Ok, thanks.   This ringer box was actually made by Automatic Electric, no S-C, but it is entirely possible that the phone company used mixed equipment.  It was an independent company, not part of the Bell System under AT&T, and these phone companies often bought whatever equipment was available at the right price.

Unfortunately, this is also a frequency-selective ringer.  I can't quite make out the numbers on the label around the ringer coil, but the construction tells me so.  Seems to be one of the higher frequencies as well. You will be able to read the numbers.  The first line should tell the frequency.

[unbeldi]

So, have you started cleaning up the telephone set a little?
Despite the ringing issue, it could still be a nice and usable instrument.

[dsk]

This diagram contains the same potted network, even when the phone is a 1543.  (do not click on the link cut and paste in the browser makes it work different)
http://www.telephonecollectors.info/index.php/browse/wiring-diagrams/stromberg-carlson/doc_download/2066-1543-1544-1546-1553-and-1556-telephones-1543w-tl

I did not find a 1443 diagram with this network, but i am sure it is somewhere.  This network seems to be fully automatic compensated!    The ringer may be problem, or at least a challenge.  A greater capacitor may make it ring, but not with the right sound.  (I would try up to 2.2  microfarad in steps depending on what I have) 

Here you have a circuit of 500 type quality, but the special SC design.  This is a between everything design and could possibly end up as rare.

dsk