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Stromberg Carlson 1243 Help - Have Dial tone now but get "number not in service"

Started by BackInTimemachines, July 30, 2021, 04:19:02 PM

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BackInTimemachines

Hi All - thanks fo rthe help on the previous handset question.

The Stromberg now gets a dial tone when I pick-up the handset! Progress. Trying to call the line it was plugged into, I get no ring. Trying to dial out - I can only dial (any) four numbers on the dial and the automated operator voice (which I can hear now) cuts in with "the number you have called has been disconnected.." message.  It doesn't seem to matter which number I dial - once I get to fourth digit it goes to this message.

I'm wondering if somehow the dial is not calibrated correctly or some other issue that is dial related?

Any thoughts or suggestions what to try next?

Thanks!

TelePlay

Find an analog large faced clock with a second hand.

Dial 0 and do not release the finger wheel until the second hand ticks.

The dial should come to a stop when the second hand ticks off the next second.

If so, the dial speed is about 10 pulses per second, factory spec.

If it takes more than a second for the dial to return to a stop, your dial is too slow (dirty, dry or needs lubrication or both.

Search the forum for the word "audacity" and you will get many topics on how to accurately determining the dial's actual speed.

There are many topics in the dial cleaning board

http://www.classicrotaryphones.com/forum/index.php?board=25.0

to get you started on that if you need to restore the dial, or simply send it along with $6 to Steve Hilsz (in the vendor board).

BackInTimemachines

Thanks! I assume any timer, like a chronograph, can be used to measure?

I'll give it a look later this morning!!

BackInTimemachines

Actually just timed it now - completed the dialing right at 1 second - so looks like the dial is on spec.

I should probably double check the wiring again from the dial mechanism to the network block.

Also, wondering how I can check if the ringer is working? Would there be a resistance across the two wires leading to it if the ringer is working or no measure if the ringer coil is open?

I also thought about putting ~75-80 VAC set up on the ringer wires and see if it is moving...

dsk


RB

There should be a number on the side of each ringer coil, assuming you have a 2 coil ringer???
And yes, If you put an AC signal across it, it should ring.
I keep a small magneto on the wall, with the wires hanging down to my bench for just that purpose. :)
Also, chk the blades on the dial. One may be bent and not functioning correctly.
Call the phone from your cell phone, after you hear it ring a couple times, "on the cell phone",
pick up the Stromberg, and see if you can talk to yourself.
But do it when you are alone. You don't want the men in white suits to come a callin. ;)
Just kidding. They won't come get you just for having a conversation with yourself...
Unless you do it too much, and your wife starts to suspect something. LOL. ;D
If you do determine the dial is not working correctly, Steve is your man!

rdelius

As  factory wired, SC 1243s are wired for a 3 wire line cord for grounded ringing. You might need to strap the gnd terminal to l2 on the network. Those old potted networks can also have a bad capacitor ,

TelePlay

Quote from: BackInTimemachines on July 31, 2021, 03:09:15 AM
Thanks! I assume any timer, like a chronograph, can be used to measure?

It's a much shorter second hand so I would think harder to see. A 12" diameter analog wall clock has a 5" second hand that is visually more accurate. This trick is impossible to do with a stop watch due to reaction time. Visual movement of a tick to release and listening to the dial stop while watching the second hand do its next second tick is the only way to use that trick. And, then, it does not give the results you get from recording the break/make spikes using Audacity, as can be explored in the multitude of topics in that dial child board.

Close up Images of your dial front and back would help us know what you are working on, SC made several different types of dial mechanisms.

I suspect you have an electric circuit issue, not a speed issue if close to being 10 pulses per second on the speed test.

Something as simple as using a piece of standard paper card stock to run between the leaf switch contacts may remove built up crud allowing better pulsing contact while dialing. DO  NOT USE abrasive paper or metal of any kind in that will remove the rare earth metals used to coat the contacts when built to prevent contact point corrosion. Doesn't take much to remove that rare earth coating to ruin the dial. A strip from a 3x5 or 4x6 note card is card stock.

If after cleaning the contacts by rubbing the card stock through the closed contacts 3 or 4 times each and you still have the issue, it's on to the next steps suggested above.

BackInTimemachines

Good suggestions from ALL! Thanks - I'm getting to work checking the dial and ringer functions first.  I will look at the gorunding as well - I have a three line (red, green, yellow) line cord.

BackInTimemachines

Quote from: rdelius on July 31, 2021, 08:18:41 AM
As  factory wired, SC 1243s are wired for a 3 wire line cord for grounded ringing. You might need to strap the gnd terminal to l2 on the network. Those old potted networks can also have a bad capacitor ,

I checked while working here - right now, Yellow ground at "G" is NOT strapped to "L2". So, if I tried this in a modern (1980s) wall jack - is that normally wired for 3 with ground or no??

TelePlay

This old but very good topic shows how a phone with a 3 wire line cord may have the yellow wire connected to G and the ringer Black Wire connected to G.

Simply move the black ringer wire from the G terminal to L1 to put the ringer into a 2 wire line cord set up.

http://www.classicrotaryphones.com/forum/index.php?topic=15870.0

L2 has the red line cord wire which connects to the red ringer wire.

L1 has the green line cord wire which connects to the black ringer wire.



This is for a WE 500 circuit so you will have to translate the idea to your SC network but the basic conversion is simple, put the ringer back into the red/green line cord connections by having one ringer wire attached to the red line cord network terminal and the other ringer wire attached to the green line cord network terminal.

TelePlay


BackInTimemachines

Some photos of the network block (number matches the diagram), ringer, and back of dial.

Yes indeed - I looked over the diagram and noticed that strap once @rdelius mentioned it. My phone is NOT connected there so I suspect it was removed from a party line at some point and not set up for bridged ringing. So, it needs to run through those capacitors so a strap running from G to L2 should connect it properly.

The next trick is the right frequency. There is a label on the bottom of the ringer says 62 ~25 which I think would mean ringer model number 62 and 25Hz which should be OK on US lines?? Of course using the lowered household AC voltage wave at 60Hz only made the ringer vibrate slightly because it's the wrong frequency. But I think the slight vibration means its good.

I did run a clean thin piece of paper through the contacts on the dial and there was a little bit of black dirt that rubbed off. Maybe that will help with the dialing. Dial is turning quiet and smoothly.

TelePlay

A 25 Hz frequency ringer should work on a POTS 20 Hz line.

60 Hz is over powering or not coming close to matching the ringer since it is not a 66 Hz frequency ringer.

rdelius

i would reroute the dial wires so that they point above the dial instead of across the dial. when the cover is screwed down,the wires are not as likely to interfere with  the dial contacts