stromberg carlson 1243 - dial tone, but nothing else

[goamules]

Hi all,
by way of introduction, I am a former Electronics Technician in the Navy.  It's been a long time, but I remember troubleshooting.  I also love antiques, and shoot antique wooden cameras with wetplate collodion, get old Coleman lanterns working, etc.  Anything old, I love!

My entry to this great forum is to ask for help.  I have a stromberg carlson 1243 I bought with clipped wires.  Cosmetically, all it needed was a little polishing, I used Mothers, followed by a good wax.  Here it is. 



When I bought it, I discovered the receiver and transmitter elements were missing.  So I bought another 1243 for parts.  Now, I've wired it according to the schematics found here, and got a dial tone.  So that works!  What doesn't:

1. I cannot hear my voice, so I'm thinking the transmitter is bad.  But I don't know how to check, I did put a multimeter on the element, and when I speak, I get resistance deflection.  I have wired the parts phone in to line and handset, and it gives the same symptom. I assume I should hear my voice in the earpiece, like a normal phone?

2. No ring.  I tried jumping the Line In Yellow and Green (read that here) to no avail.  The parts phone seemed to want to ring, when wired.  When I dialed from my cellphone, and picked up with the two disconnect buttons, it would do a quick ring....right when I picked up.  I have had that affect stop now though.  The "good" phone has no ring at all.

3.  No dialing.  I hear clicking when I dial a number, but it stays on a dialtone.  Nothing happens. 

I appreciate all you techs out there helping a former one....who never worked on phones!

Garrett 

[tallguy58]

Welcome to the land of information.
The guys here have fixed everything from  two soup cans with a piece of string to network systems.

Nice looking phone, by the way.

[goamules]

Thanks.  I figured none of us is smarter than all of us!  One troubleshooting clue, both phones appear to be jumpered/wired the same.  And when I hook them up, both give the same symptoms. 

[goamules]

So, dive right in, who can help me?!

[dsk]

Welcome!
It looks like it is some different wiring diagrams for those, the number on the boxed network may be the key, mine are stamped in red: 200595  B, and are wired with straps as marked red at this diagram. 
The ringer may be connected to a tube, or even depending on a different frequency, a so called tuned - or frequency - ringer.  Mine rings loud at frequencies from 15 - 30 Hz (not tested outside this span)

The transmitter element are in series with the DC path of the telephone, removing the element should break dial tone. 

A simple test of transmitter and receiver element may be to connect them in series, and in series with a battery supplying 20-50 milliamps.  (more may harm the transmitter) Approx 3-5 V use to be OK. Then you should hear yourselves well.

dsk

[poplar1]

If you can provide photos of the inside of each phone, perhaps we can tell if the ringers are the frequency-selective type used only on certain party lines.

[goamules]

I'm happy to show any pictures you need.  Both below.  DSK, I show all the straps in place on the left side that your schematic shows, both phones.  No straps on either phone on right side.  They are consistent, as is my symptoms.  As far as applying different Freqs, miliamps, etc....I don't have a bench, and haven't done electronics in 25 years.  So the simpler the better.  I could hook up the transmit-receive in series, and appy a 3VDC batter, if that's what you mean.  So center connector to center to positive, then outside connector (body) to outside to negative?  Right?

[poplar1]

The folded up paper is the wiring diagram. The diagram should show the strap needed for "Bridged Ringing" or individual line--perhaps a strap from L-2 to G? Originally, it probably had a 3-conductor cord, and the wire on G could be connected to the same screw as the L1 or L2 wire at the wall. When using a 2-conductor cord, you have to modify the wiring inside the phone in order to make it ring.

However, that is a harmonic ringer, which means it is designed to respond only to one frequency, but you may be able to make it work on your line with some adjustment.

[goamules]

OK, I tried all the straps.  L2 to G, and C1 to C2.  Didn't change the ring prob.  I wonder, does anyone in the US have one of these 1243s working?  Couldn't I just duplicate what their wiring shows?  I mean, both of these phones, made probably years apart and from two different areas, both were wired the same, from what I can tell.  I didn't trace every line, but they look the same. 

[poplar1]

The lower picture (with the new cords) shows the kind of ringer that should work on your line. However, you will need to strap L2 and G, or connect the green and yellow wires of the brown cloth line cord together at the wall. Strapping C1 and C2 together doubles the capacitor value, which may also help ringing.

[poplar1]

Check the resistance of both ringers to make sure the coils aren't open.

[goamules]

OK, I got 3,000 Ohms with both ringers. 

[poplar1]

If you want to isolate the ringer circuit: The ringer is connected to L1 and, in series with the capacitor, to L2.

The ringer is in series with either 0.5 uF or 1.0 uF capacitor (2 x 0.5). The red ringer wire connects (through strap 1-3 and internal network connection) to L1 and to the capacitor(s) at C-2 , and the other side of the capacitor(s) connects  (through internal network from C2 to G and strap from G to L2) to L2.

[poplar1]

I'm looking at this diagram, so hopefully it's not different from the one folded up in your phone. In any case, you can also connect the red ringer wire directly to L1 rather than on the left side of the network.

http://www.telephonecollectors.info/index.php/document-repository/doc_details/2086-1243a-sc1243a-tl

Rather, this one:

http://www.telephonecollectors.info/index.php/document-repository/doc_details/2087-1243-1250-sc1243-50-tl

[unbeldi]

This No. 200595 B network was commonly used on many (or all?) of the 12xx-series telephones in the 1940s, common battery and local battery, desk and wall phones.

The diagram posted by Dsk (post #6) is probably the correct one, should work at least.

The type of ringer should be stamped on the bottom side, against the mounting base plate, or perhaps also visible through a slot in the base, stamped on the ringer magnet.  I have a box full of these, and they are all marked clearly.  But as Poplar pointed out the one with the large striker weight is a frequency ringer and the other one is a biased straight-line type.