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old Danish phone

Started by long jumper, August 15, 2022, 04:40:46 PM

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TelePlay

Don't know European phones but the two voltages I've ever seen is 60-90 VAC to operate the ringer and 3-6 VDC for the talk circuit. Once the handset is lifted, AC does not travel through the dial. Maybe others know better.

From the diagrams provided, it seems the counter operates through the dial which would be talk voltage, 3-6 volts DC.

Interesting part is that the counter increments on the first number dialed and whatever is keeping the counter from increasing on the next numbers dialed is cleared for the phone's next use.

Dial pulses are the breaking and making of continuity on the low DC voltage circuit. The counter see the first number dialed. An interesting problem.

dsk, and maybe others, know the electrical circuitry best.

long jumper

I am fairly new to all this but like i stated  applied 6 volt DC no movement. The shaft turns  freely. Can't think of anything but counter being defective.

TelePlay

In the wiring diagram posted by dsk,

http://www.classicrotaryphones.com/forum/index.php?topic=26510.msg257989#msg257989

the counter circuit shows an RC circuit that has to be charged from line voltage. The capacitor is discharged through the counter when the dial is first turned and the talk circuit shunt leaves are closed.

That would indicate why the counter only works on the first number dialed. When it is discharged when dialing the first number, the "counter" capacitor will not be charged enough to operate the counter for 5 minutes.

As such, several short calls could be made without being counted as long as they are dialed in less than 5 minutes between each dialing, each of which discharges the capacitor so the 5 minute window starts over and the call is not counted.

All assumes the counter is working but we don't know how the mechanical mechanism inside the housing works.

Being in your hands, only you can try different circuits and tests.

long jumper

Yes,Tried charging the capacitor for over 10 minutes but could not break dial tone when dialing.I still think counter is broke. Out of curiosity wonder how this was wired to work originally?

TelePlay

Quote from: long jumper on September 24, 2022, 06:25:27 PMOut of curiosity wonder how this was wired to work originally?

Yes, that would be a good thing.

Now, being and "old" counter, is it possible to remove the counter and see if it can be taken apart exposing the workings?

long jumper

Removed from base plate then removed  base of counter there was a coil inside but was not able to dis mantel. I think I am done. If anyone has any suggestions let me know. thanks for  everyone's  help


TelePlay

For posterity, can you post images of the counter, external and internal, from different angles?

A coil inside would indicate a solenoid type mechanism.

long jumper

Yes I might try again in a few days

rdelius

You might check the line polarity with respect to the capacitor's polarity

TelePlay

Quote from: TelePlay on September 24, 2022, 07:27:12 PMA coil inside would indicate a solenoid type mechanism.

Have you tested the coil for continuity?

Worst case is a broken wire in the winding, hard to fix.

Best case is the end of the magnet wire, over the years of changing temperatures, has broken away from its solder point. Magnet wire is coated with varnish so only the very small cross section cut end, the cross section of the wire, is soldered to the wires going to the terminals. The varnish acts like a non-conductive tube allowing the inner metal conductor to break free of its solder point creating a short. Simply refreshing the solder joint eliminates that short.

I have had a couple of old subset ringers that had that happen to them. Re-soldering, refreshing the magnet wire joint fixed the short. This may or may not apply to your counter.

I found this text in a reply posted by me in September 2018 about magnet wire soldering issues:

QuoteAs for re-soldering the magnet wire to the ringer leads, while I was given credit for the tip, the credit really goes to Jeff Lamb, ktownphoneco, who made me aware of this when I had a 600 subset type ringer that was dead. As he explained to me, to save time when first made by WE, the magnet wire was just cut and soldered to the ringer wire. To save assembly time, the sides of the magnet wire were not stripped of their varnish or enamel so that only the end cross section of the very thin wire would bond to the solder, make the joint. Over time, with temperature changes, the magnet wire within the solder joint would shrink in length and after time could cause that very small cross section of the magnet wire to break free from the solder leaving the magnet wire inside of the varnish or enamel coating tube insulating it from the solder. Re-soldering such a joint would again bond the magnet wire with the solder and the ringer wire creating a near resistance free circuit.


long jumper

Sending photos of counter. Coil seems good applied 6 V DC nothing movement nothing clicking. Cannot figure out how to get this cover off without that shaft being there in the way
Will post photos

long jumper

There's got to be a way to remove the shaft. Then cover would pull off. It's the only thing holding the cover on

TelePlay

Thanks for the counter images. I don't have a clue of what to do next.

long jumper

There is magnetic hold when energized,mechanism will not let numbers move until 6 volt source is removed when using small screwdriver to advance digits. Do you think dsk would know how to remove cover or any one else?

dsk

I have never removed that cover, but one on/off pulse lets my counter add 1.