Hi all, I have a 1953 Stromberg Carlson 1243WK phone I am trying to restore as a surprise for my wife. I'm hoping some members might be able to point me in the right direction in troubleshooting a wiring issue in updating it. I purchased a 4 wire modular cable to replace the original 4 prong plug. I wired the phone according to the attached diagram as it is the only one I found which matched what parts this phone has. I do not know if someone previously modified this or if it was this way from the factory but the dial has 5 wires instead of the usual 4 I found on almost all diagrams I found for this model phone online. In taking it apart to clean and paint I took pics and looked up the model numbers of the parts. It appears to have a regular 200595B network but has a Western Electric P-339952 dial (5 wires instead of the usual 4) and Sig Eng VP2-1 (single bell) ringer instead of the usual two bell ringer. When I plug it in to a standard land line I get a good dial tone and and able to dial out fine, speak, hear and hang up at the end of the call. On the other hand if I call in to it the bell does not ring (the plunger is free moving), if I pick up while in the call I can speak and hear fine but if I hang up the Stromberg it does not disconnect. I can pick up again and the other phone is still on the line. Only when the other phone hangs up does it disconnect. Has anyone run into this issue? I'm wondering if the network is bad. I have looked all over but haven't found anything about testing the network or other components. Any help would be greatly appreciated. Steve
Hi, and welcome to the forum. Looks like the ringer circuit is the issue. The ringer is an army type, and it may need more pwer than an ordinary ringer, so it may depend of the ringing current source. The Straps L2-G and C1-C2 is important. I can only see one wire from the ringer, but the other may just be outside the picture.
I guess you should concentrate around the ringer as the first thing. I do not believe the capacitors are bad, but it may be the next to check out.
dsk
Interesting, do you know what voltage that type of ringer would run at? I could find no specs on it anywhere. I could disconnect it and try testing it with a power supply to see if it rings on it's own. Steve
Are you using a standard POTS landline or do you have a VOIP line?
That "ringer" appears to me as a buzzer as often used in key systems. It is a part used by the Army Signal Corp. Perhaps it was installed to operate from a special signaling circuit with a DC power supply. Is it even connected across the line ?
It should not be too hard to find the proper straight-line ringer for these sets.
Quote from: unbeldi on June 13, 2017, 09:44:43 AM
That "ringer" appears to me as a buzzer as often used in key systems. It is a part used by the Army Signal Corp. Perhaps it was installed to operate from a special signaling circuit with a DC power supply. Is it even connected across the line ?
It should not be too hard to find the proper straight-line ringer for these sets.
I believe it is the ringer used in Signal Corps EE8 field telephones. The top is a gong with a notch in the edge. Flaps produced by slotting the edge are bent inward to provide a notch with flat side surfaces which the clapper strikes. Impedance may be lower than a usual ringer to operate on lower voltage from a magneto but probably not very low since some EE8 circuits had multiple phones connected.
S-C 1243s are most commonly equipped with AE Type 24 dials which have a 3-contact normally open contact spring set for shorting the receiver and transmitter when the dial is off normal. This method typically only requires 4 dial leads. A WECo dial puts a normally closed contact in series with the receiver thus requires a 5th lead to the dial.
The statements about not releasing the line are unclear to me but if the ringer has a cap in series and the cap is not shorted or leaky this ringer should not be any problem.
It hard to judge the size of this VP2, but it seems only about an inch across. The manuals (ca. 1950) I have of the EE-8 types specify an MC-131 for the ringer, which is a single gong used as cover over the two-coil motor and looks quite different.
Quote from: unbeldi on June 13, 2017, 10:18:55 AM
It hard to judge the size of this VP2, but it seems only about an inch across. The manuals (ca. 1950) I have of the EE-8 types specify an MC-131 for the ringer, which is a single gong used as cover over the two-coil motor and looks quite different.
If the screws mounting the network visable above are #6 the shanks are about 1/8" dia. and heads are about 1/4-5/16" diameter and so are the ones holding the gong (if that's what it is) in place. From that it seems to me to be a lot larger than 1" dia., like 2 or 3". The MC-131 was about 3".
One could also pull a 1243 and look at the hole pattern for the grommetted base plate holes, which I think are for the ringer.
Yes, it is a ringer. Probably army surplus and installed by a refurbisher. I've seen these in other 1243s.
is there a strap connecting L2 to G?
Is the ringer connected to 3 and C1? (It should also work if connected to L1 and C1.)
BTW, the dial is a Western Electric 6A.
Quote from: QUIKRIDE86 on June 13, 2017, 09:06:43 AM
Interesting, do you know what voltage that type of ringer would run at? I could find no specs on it anywhere. I could disconnect it and try testing it with a power supply to see if it rings on it's own. Steve
The ringer is the type used in US army field telephone EE-8, mine has a DC resistance of about 1200 ohms. The spec says 50 V at 20Hz.
I tried to measure mine together with a 1uf cap, and got something like 1.6 REN load.
That load may be tough for an ATA, but a POTS line should not make any problems.
If you remove the gong you could see if the armature is moving freely, and it should buzz instead of ringing.
dsk
Quote from: TelePlay on June 13, 2017, 09:39:41 AM
Are you using a standard POTS landline or do you have a VOIP line?
Standard POTS line to test (old analog line at my job). At home I do not have a landline so I am planning to use this gateway (http://www.myxlink.com/xlink_bt.aspx) to connect through my cell phone.
Quote from: Alex G. Bell on June 13, 2017, 10:25:31 AM
If the screws mounting the network visable above are #6 the shanks are about 1/8" dia. and heads are about 1/4-5/16" diameter and so are the ones holding the gong (if that's what it is) in place. From that it seems to me to be a lot larger than 1" dia., like 2 or 3". The MC-131 was about 3".
One could also pull a 1243 and look at the hole pattern for the grommetted base plate holes, which I think are for the ringer.
Correct, it is about 2" across.
Quote from: dsk on June 13, 2017, 12:08:35 PM
The ringer is the type used in US army field telephone EE-8, mine has a DC resistance of about 1200 ohms. The spec says 50 V at 20Hz.
I tried to measure mine together with a 1uf cap, and got something like 1.6 REN load.
That load may be tough for an ATA, but a POTS line should not make any problems.
If you remove the gong you could see if the armature is moving freely, and it should buzz instead of ringing.
dsk
I had it apart to clean and the armature is moving freely.
Quote from: unbeldi on June 13, 2017, 09:44:43 AM
That "ringer" appears to me as a buzzer as often used in key systems. It is a part used by the Army Signal Corp. Perhaps it was installed to operate from a special signaling circuit with a DC power supply. Is it even connected across the line ?
It should not be too hard to find the proper straight-line ringer for these sets.
I checked and it is wired red to #3 and black to C-2.
Quote from: QUIKRIDE86 on June 13, 2017, 02:58:02 PM
I had it apart to clean and the armature is moving freely.
I suggest posting a photo of the underside. I'd expect that like the MC-131 it has two side-by-side coils and a permanent magnet around the back (as best as I remember the construction from years ago), no interrupter contacts in series with the windings.
Quote from: Alex G. Bell on June 13, 2017, 03:03:17 PM
I suggest posting a photo of the underside. I'd expect that like the MC-131 it has two side-by-side coils and a permanent magnet around the back (as best as I remember the construction from years ago), no interrupter contacts in series with the windings.
I can take a pic when I get home but what I saw when it was apart was a single coil (centered under the gong)with a freely moving pole piece that extended out both sides and was able to contact the gong either direction.....also there was no spring attached to it.
Do you have a meter? If yes, could you measure the resistance between black and red? You do not have to remove the wires.
dsk
Quote from: QUIKRIDE86 on June 13, 2017, 03:10:01 PM
I can take a pic when I get home but what I saw when it was apart was a single coil (centered under the gong)with a freely moving pole piece that extended out both sides and was able to contact the gong either direction.....also there was no spring attached to it.
OK. I've seen bells or ringers with that kind of construction. More important is whether it contains a permanent magnet and/or any contacts, and somewhat secondarily, the resistance. If it
contains contacts certainly or
does not contain a permanent magnet perhaps it's not a "magneto ringer" and not intended for operation from low frequency high voltage AC.
However no issue with the ringer would be logically related to this:
1) "When I plug it in to a standard land line I get a good dial tone and am able to dial out fine, speak, hear and hang up at the end of the call. "
2) "On the other hand if I call in to it the bell does not ring (the plunger is free moving),"
3) "if I pick up while in the call I can speak and hear fine but if I hang up the Stromberg it does not disconnect. I can pick up again and the other phone is still on the line. Only when the other phone hangs up does it disconnect."
(1) and (3) are
at first glance contradictory to each other, depending on exactly what you mean by "other". Either it releases the line or it does not. If another phone is off hook on the
same called line of course the line will not be released until both hang up. However release of the connection is normally mostly controlled by the
calling end, with timeout from the called end, so unless the
called phone hangs up for 20-35 seconds the incoming call will still be there when the called phone goes off hook again if the caller did not hang up in the mean time.
So you need to clarify what you mean by this. One interpretation is that this is perfectly normal and any phone would do this.
Note the heavy black lines between L2--G and C1--C2 in the diagram. Did you install those two straps (short wires)?
Quote from: Alex G. Bell on June 13, 2017, 03:57:26 PM
OK. I've seen bells or ringers with that kind of construction. More important is whether it contains a permanent magnet and/or any contacts, and somewhat secondarily, the resistance. If it contains contacts certainly or does not contain a permanent magnet perhaps it's not a "magneto ringer" and not intended for operation from low frequency high voltage AC.
However no issue with the ringer would be logically related to this:
1) "When I plug it in to a standard land line I get a good dial tone and am able to dial out fine, speak, hear and hang up at the end of the call. "
2) "On the other hand if I call in to it the bell does not ring (the plunger is free moving),"
3) "if I pick up while in the call I can speak and hear fine but if I hang up the Stromberg it does not disconnect. I can pick up again and the other phone is still on the line. Only when the other phone hangs up does it disconnect."
(1) and (3) are at first glance contradictory to each other, depending on exactly what you mean by "other". Either it releases the line or it does not. If another phone is off hook on the same called line of course the line will not be released until both hang up. However release of the connection is normally mostly controlled by the calling end, with timeout from the called end, so unless the called phone hangs up for 20-35 seconds the incoming call will still be there when the called phone goes off hook again if the caller did not hang up in the mean time.
So you need to clarify what you mean by this. One interpretation is that this is perfectly normal and any phone would do this.
The ringer doesn't have contacts under the bell or gong. I will check the resistance when I get home and snap a couple pics. When I moved it with no power I did feel some 'pull' like there was a magnet involved. I will check to see if the pole is magnetized also. As for the statements i made I meant that it seemed that on calling FROM the phone to another (my cell) I was able to hang up disconnecting the call but when I called the Stromberg from my cell phone and hung up the Stromberg it did not disconnect the call. From what you said about it taking 20-30 sec for the disconnect this makes more sense to me (and apparently is not a problem with the phone). I'll try to check those other things about the bell soon (about an hr or two) when I leave work. Steve
Quote from: poplar1 on June 13, 2017, 04:35:40 PM
Note the heavy black lines between L2--G and C1--C2 in the diagram. Did you install those two straps (short wires)?
I don't remember it having a strap from L2 to G but I'll check that when I return. It definately has a strap from C1 to C2 though. Steve
Quote from: QUIKRIDE86 on June 13, 2017, 04:40:07 PM
The ringer doesn't have contacts under the bell or gong. I will check the resistance when I get home and snap a couple pics. When I moved it with no power I did feel some 'pull' like there was a magnet involved. I will check to see if the pole is magnetized also. As for the statements i made I meant that it seemed that on calling FROM the phone to another (my cell) I was able to hang up disconnecting the call but when I called the Stromberg from my cell phone and hung up the Stromberg it did not disconnect the call. From what you said about it taking 20-30 sec for the disconnect this makes more sense to me (and apparently is not a problem with the phone). I'll try to check those other things about the bell soon (about an hr or two) when I leave work. Steve
Since apparently you have a DMM or VOM, the best way to satisfy yourself that the S-C is releasing the line when it should is to put the DMM/VOM on a range > 50VDC properly poled so the meter goes up scale. When the phone is on hook you will see ~48-50VDC on a telco analog line. When the phone is off hook you will see typically 6-12V, even as low as 2V on a long line with a low resistance speech circuit. The voltage will return to ~48-50V immediately when the cradle switch is operated.
You can also test for ringer capacitor leakage by putting the meter in series with the phone still set to VDC. If the capacitor is good (not leaky) the meter will eventually settle near 0V once the capacitor charges. If the voltage is not 0 or close to it the capacitor is leaky or there is some other leakage fault.
This is a much more valid test than measuring resistance since leakage tends to be much greater with greater applied voltage and VOMs and DMMs typically apply 1½-3V to avoid damage to semiconductors.
Quote from: QUIKRIDE86 on June 13, 2017, 04:45:14 PM
I don't remember it having a strap from L2 to G but I'll check that when I return. It definately has a strap from C1 to C2 though. Steve
If the phone originally had a 3-conductor hardwired cord connected to L1, L2 and G -- but no strap from L2 to G --then to make the ringer function, it would have been necessary to connect the wires from L2 and G together at the wall connecting block.
When converting a phone from hardwired to modular, it is necessary to bridge the ringer circuit and talk circuit inside the phone.
Quote from: Alex G. Bell on June 13, 2017, 10:25:31 AM
If the screws mounting the network visable above are #6 the shanks are about 1/8" dia. and heads are about 1/4-5/16" diameter and so are the ones holding the gong (if that's what it is) in place. From that it seems to me to be a lot larger than 1" dia., like 2 or 3". The MC-131 was about 3".
One could also pull a 1243 and look at the hole pattern for the grommetted base plate holes, which I think are for the ringer.
Just an FYI it measures 2-1/4" approx. It does look as if the ringer was replaced by someone. On closer inspection as I unscrewed it from the base I could see it appears someone enlarged the holes with a dull pair of scissors. LOL. I cleaned up the holes with a countersink before replacing the ringer assembly.
Quote from: Alex G. Bell on June 13, 2017, 03:03:17 PM
I suggest posting a photo of the underside. I'd expect that like the MC-131 it has two side-by-side coils and a permanent magnet around the back (as best as I remember the construction from years ago), no interrupter contacts in series with the windings.
I checked and it definitely is one coil on this one. No contacts.There is a magnet in the cad plated side to the right in the photo. The 'striker' is not magnetized and appears to be the same both ends.
Quote from: dsk on June 13, 2017, 12:08:35 PM
The ringer is the type used in US army field telephone EE-8, mine has a DC resistance of about 1200 ohms. The spec says 50 V at 20Hz.
I tried to measure mine together with a 1uf cap, and got something like 1.6 REN load.
That load may be tough for an ATA, but a POTS line should not make any problems.
If you remove the gong you could see if the armature is moving freely, and it should buzz instead of ringing.
dsk
I checked the resistance on this one and it came out at 2.7k ohms. Don't know if that's good or bad.
Quote from: poplar1 on June 13, 2017, 05:02:16 PM
If the phone originally had a 3-conductor hardwired cord connected to L1, L2 and G -- but no strap from L2 to G --then to make the ringer function, it would have been necessary to connect the wires from L2 and G together at the wall connecting block.
When converting a phone from hardwired to modular, it is necessary to bridge the ringer circuit and talk circuit inside the phone.
Yup, looks like the wires were connected at the block! I added a jumper across G and C-1 (which also jumps to C-2). Would this be correct?
2.7K is quite reasonable. Without a bias spring it may tap when other phone seize and release the line or rotary dial but it appears to be a "magneto" ringer. So next focus on whether it seizes and releases the line properly based on DC voltage measurement and if that's okay why it does not ring is the only real problem.
Quote from: QUIKRIDE86 on June 13, 2017, 07:56:05 PM
Yup, looks like the wires were connected at the block! I added a jumper across G and C-1 (which also jumps to C-2). Would this be correct?
Opps.....just realized I connected the wrong ones poplar1. I removed the jumper I put between G and C-1 and moved it to between L2 and G. Steve
Sorry for the multiple posts everyone. Just wanted to address everyone's comments once I got back home from work. With these changes I will bring the phone to my job tomorrow to try it out. If it doesn't ring I'll try and get the voltages to further troubleshoot. Steve
Quote from: QUIKRIDE86 on June 13, 2017, 08:18:13 PM
Opps.....just realized I connected the wrong ones poplar1. I removed the jumper I put between G and C-1 and moved it to between L2 and G. Steve
Now that you have eliminated the "air gap" between L2 and G, you can remove the yellow wire from G. (You might insulate and store it.)
Quote from: poplar1 on June 13, 2017, 08:33:14 PM
Now that you have eliminated the "air gap" between L2 and G, you can remove the yellow wire from G. (You might insulate and store it.)
OK, will do!
Quote from: QUIKRIDE86 on June 13, 2017, 08:22:08 PM
Sorry for the multiple posts everyone. Just wanted to address everyone's comments once I got back home from work. With these changes I will bring the phone to my job tomorrow to try it out. If it doesn't ring I'll try and get the voltages to further troubleshoot. Steve
You can certainly determine whether it's releasing the line properly with just the resistance measurement ranges on a DMM or VOM even though not particularly valid leakage tests nor of course ringing.
I guess you have solved it!
That is not a ringer from EE8 but rather from another like AN/GRA-6.
Should work!
dsk
I just got in to work where I could test it and IT WORKED! :D Finally found what was wrong due to all your help guys. Thank you so much for all the advice. The amount of knowledge on here is amazing.....glad I found this group.
Quote from: dsk on June 14, 2017, 12:39:52 AM
I guess you have solved it!
That is not a ringer from EE8 but rather from another like AN/GRA-6.
Should work!
dsk
Yes! Seems it was that missing jumper (L2-->G) due to the original line having it jumped at the wall jack. Glad poplar1 gave that heads up. I was totally missing it.
Congratulations!
Found some data from an army manual: TM11-5038 p.74
RINGER, telephone: 20 cyc harmonic; non adi
armature; 2555 ohms +/-10%; 2 1/2" diam x 1" h
max o/a; 2 1/2" diam gong; footed bracket mtg, two
#8-32 holes on 2" mtg/c; coil varnish impr and
dipped; Fed Tele & Rad part/dwg #GH-1535-2.
dsk
Quote from: dsk on June 14, 2017, 10:10:11 AM
Congratulations!
Found some data from an army manual: TM11-5038 p.74
RINGER, telephone: 20 cyc harmonic; non adi
armature; 2555 ohms +/-10%; 2 1/2" diam x 1" h
max o/a; 2 1/2" diam gong; footed bracket mtg, two
#8-32 holes on 2" mtg/c; coil varnish impr and
dipped; Fed Tele & Rad part/dwg #GH-1535-2.
dsk
Oh cool! Thanks for looking that up, good to know. The 2774ohms I got is well within spec then!
I have seen those ringers installed in Stromberg Carlson and AE phones before. Since these phones were often used on party lines, perhaps a previous "refurbisher" was fond of using them to replace frequency ringers.
Quote from: mentalstampede on June 14, 2017, 11:43:05 AM
I have seen those ringers installed in Stromberg Carlson and AE phones before. Since these phones were often used on party lines, perhaps a previous "refurbisher" was fond of using them to replace frequency ringers.
Looks that way. They did a pretty rough job of hogging out the holes for it. It's all good now!