News:

"The phone is a remarkably complex, simple device,
and very rarely ever needs repairs, once you fix them." - Dan/Panther

Main Menu

PTT Nederland Standard 1954 Does not Ring (and a mysterious plug?)

Started by Budavox, November 06, 2021, 11:32:26 AM

Previous topic - Next topic

countryman

while the shown UK mains plug has a bigger and longer Earth prong, the Tripolari connector has 3 equally sized prongs.
https://phone-jack.org/italian
https://it.wikipedia.org/wiki/Presa_telefonica_tripolare

FABphones

Side by side images for comparison.

Italian Tripolare to left.
Old style U.K. mains plug to right.
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

dsk


Budavox

Quote from: RB on November 06, 2021, 08:37:34 PM
Do you have an ohm meter?
check the coils, looks like 500 ohms each.?
Do you have a
dc power supply? 18-24 volts? put across the coils and see if the hammer moves.

Hello all,

I've tried reading the coil/resistor based on the numbering that @dsk sent using analog ohmmeter,
the result is:
1-2 = 5
1-3 = 5
2-3 = 0
1-4 and 3-4 = the ohm meter indicator just jumped a bit and back to normal..

However in the ohmmeter settings I used x10k which means number in the ohmmeter will be multiplied by 10.000
Is it possible that the coil is 50000 ohm?? This is cheap ohmmeter anyway.. could be wrong  ;D
with other settings the ohmmeter needle would not move.

It seems the coil number 3 and 4 is not working?  :'( :'(
Can this be repaired...? Or replaced with a new modern resistor? Like the picture below..? Or there is a better solution without replacement? I'd really like to keep this in the original state..


dsk


countryman

Yes it looks like the left hand coil in the picture is interrupted. Can you see tiny ends of enamel insulated copper wire on the soldered terminals? If you were very lucky the wire was damaged in a way that it could be resoldered. Unfortunately thisis rarely the case. Then it would be required to unwind the coil and rewind it with the same or better new wire. Most often it is easier to just get a new ringer then.
It could be some not so bright person really hooked the phone to mains power at some point of time and the wire just melted inside the coil.
A resistor would have no benefit here - it may have the same DC resistance, but will not produce magnetism to move the clapper. Follow dsk's advice and just strap (connect together) 3 and 4. Chances are, the ringer also works with 1 coil.
Re your reading values, can you show a picture of the ohm meter?

Budavox

Quote from: dsk on November 12, 2021, 07:31:54 AM
Just strap it, and try.
Quote from: countryman on November 12, 2021, 12:52:14 PM
Follow dsk's advice and just strap (connect together) 3 and 4. Chances are, the ringer also works with 1 coil.

OMG THANK YOU VERY MUCH @dsk and @contryman~!!! You are really made my day  :) :)
I was a bit shocked when I plug the line cord and hear the hammer hit one of the gongs, then I called my house number and it ringed!!

It can really work with one coil, thank you very much.. the clapper however moves differently so I just moved gong on the right side closer to the clapper to allow it to be hit  8)

And one question, when you said strap it, how do we actually strap it?
For now I have a flexible cable, and I just put it between the coil (see picture -- the bent white cable) and make sure it has contact by measuring it with ohmmeter (now 1-4 value is same with 1-2 and 1-3)

Shouid I solder it? I am afraid I will damage it.. Can I just just a cellotape? Or are there better ways?

Quote from: countryman on November 12, 2021, 12:52:14 PM
Re your reading values, can you show a picture of the ohm meter?
It is hard to take picture when my hands are using the ohmmeter, however I provide my ohmmeter picture here.. My setting is x10k and the needle is pointing to number 5 in the scale.

countryman

Congratulations!
You only have to work on the coil that is damaged anyway, so I'd suggest to solder the wire. First start tinning the wire ends on their own (away from the eyelets), then you can solder them in place easily and without heating up the eyelets too much.

The ohm meter reading as shown would be 50.000 Ohm (50 kOhm) in fact. It should be 500 Ohm. Any chance to verify that the instrument works correctly? But never mind, the phone works now  :)

dsk

Nice to hear that it works now, I would have soldered a wire on those terminals, but be careful. I use an old solder iron of 25W, and solder the wire ends before I put them to the terminals, then the soldering goes well.

Regarding your meter, at x100 you should lay the meter on the table, short the test pins and adjust so the meter is showing 0, When metering across the coil of 500 ohms, the needle should stop close to the 5 you have shown with an arrow. When changing to another position on ohm scale, you have to repeat the 0 procedure.  The meter looks like an OK meter for a telephone collector.

Budavox

Ahh I see.. ok2 I will borrow the solder from my father, for now I just make extra bends so the little cable would push itself to the sides. So far is OK, I have turned the phone upside down and it stayed on place   :D

Anyways, I tried to dial a number but sometimes the clapper moves so it rings a bit. This condition is same if I parallel two phones using pulse dial, the other phone will ring when we dial a number from a phone -- not all phones, some of mine does not ring; or maybe the clapper moves but not far enough to touch the gongs (?)

I understand the ringing in parallel condition, the pulse sent from a phone to the telephone exchange is also received in another phone; but in this PTT phone, why is the pulse 'leaked' to the ringer? Could it be because we only one one coil now..? So not enough resistance?

It is funny though, first it was a problem that this phone could not ring, and now it rings but not in the correct moment  ;D ;D

dsk

Should not tinkle when you dial from this phone because of the hookswitch, maybe it needs to be adjusted?
The tinkle from other rotaries was seldom a problem in Europe because people only had one phone at that time.   :D

You may find an interesting thread about a similar phone here: http://www.classicrotaryphones.com/forum/index.php?topic=13772.msg144110#msg144110
An anti tinkle was made with a spring, in UK with a temperature depending resistor, and some places they used a pair of zener diodes back to back in series with the ringer.   That is the most easy solution for you between terminal 9 and 10. Voltage of zeners would probably be OK around 15 V . You may test with whatever you have, with only one zener the direction of the diode is of importance.

dsk

poplar1

Sometimes, reversing the polarity of the incoming line, or moving the gong further away from the clapper will help reduce tinkle.

Also, you could use the x1, x10, or x100 setting to measure 500 ohms rather than x10K.
"C'est pas une restauration, c'est une rénovation."--François Martin.

Budavox

Thank you @dsk,

I will look for a zener diode here.. and bridge 9 and 10 with it   :)

Would this also fix the tinkering when I rotate the dial? My problem was the telephone is tinkering itself (not another phone) when I rotate the dial to call a number..

Budavox

Quote from: poplar1 on November 14, 2021, 01:41:48 PM
Sometimes, reversing the polarity of the incoming line, or moving the gong further away from the clapper will help reduce tinkle.

Yes I was thinking the same thing.. I set the gongs further away but then the ringing would be very low (since now the ringer only work with one coil)

Quote from: poplar1 on November 14, 2021, 01:41:48 PM
Also, you could use the x1, x10, or x100 setting to measure 500 ohms rather than x10K.
I tried them all, but only with x10k the ohmmeter needle is moving  ;D ;D it might be the ohmmeter needs calibration, or I need another ohmmeter as comparison to make sure