Author Topic: German Tabletop Teilnehmer-Münzfernsprecher 55 (Hagenuk) Oslo version  (Read 3318 times)

Offline dsk

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This tabletop payphone are made for us in smaller shops etc where people may borrow it for local calls. 1 coin pr call, no time limit, but the dial has a register blocking some numbers.
The programming are made by soldering contacts.
The hook switch has a spring with some slow action to prevent dialing this way.
It has a bypass switch, and a small vault for a handful of coins.
This one are made for coins with a diameter of 22 mm. No hi-tech validator.
Mine are dated 8 70 and has never been i service.

dsk

PS shortform for Teilnehmer-Münzfernsprecher 55: TlnMü55, TMünz55. OMünz55 or Tischmünzer 55
DS
« Last Edit: November 03, 2014, 01:16:36 PM by dsk »

Offline dsk

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #1 on: November 01, 2014, 05:06:27 PM »
Here are some diagrams:

Offline JimH

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #2 on: November 01, 2014, 05:30:53 PM »
That sure is an unusual payphone.  The styling looks so dated for 1970.  I know foreign telephones always seemed a bit behind American telephones.  I wonder if they also used something like this in hotel/motels.  I remember being in some motels where they had a similar "500-like" unit right next to the "magic fingers" massage coin acceptor. 

Jim
Jim H.

Offline dsk

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #3 on: November 01, 2014, 05:51:47 PM »
They did not put much into changing design: http://tinyurl.com/ocdonrv
dsk

Offline dsk

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #4 on: November 02, 2014, 05:59:32 AM »
Have done a little testing:
The relay R of 260 ohms in series with the circuit, cause some voltage drop, and release the connection for all dialed circuits at voltagedrop, or polarity reversal, it does not do anything on an incoming circuit.  The shunting of the transmitter circuit (anti sidetone) are causing a voltage drop, "stealing" power from the circuit. This makes carbon transmitter as the only reliable transmitter, and even this makes a demand of a central battery of 48V (or at least much more than 24V.

The reverse dial face are just a glued on top of an ordinary dial.
I have not tested out all the digits it senses and let go, or block. It seems to block calls tarting with 1, 2 or 3 pulses (9,8 and 7 on the dial).  It also blocks some digits after 0 as first digit, but not all.

dsk

unbeldi

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #5 on: November 02, 2014, 08:45:41 AM »

Is something not working?

Do you have both keys? I see you have at least one.  I think the key to the coin vault is different than the side switch. The key switch on the right hand side enables and disabled the coin operations and dial blocks. When disabled, the set should work just like a W48.

When coin operation is enabled, you have to place coins (usually two) into the coin tray, dial the desired number, and when the called party answers,  you have to deposit the coins into the internal collection box by sliding the coin tray to the right with provided handles, squeezing them together. Until you do so, the transmitter is disabled, so you cannot speak with the dialed party, but you can monitor that you have the correct connection.

These coin collector telephone sets were based on the W48, and replaced their successor, the model no. 33, starting ca. 1955. They were in use until the mid 1970s when the German Post started metering local calls. The blocking dial prevented only long-distance toll calls and international calls by monitoring the first three dialed digits. The hookswitch contacts of the set are operated by a sort of air pump, that causes a delay in the operation of the hookswitch, so that it would prevent hookswitch dialing by tapping the hookswitch, so that the dial block could not be circumvented at the telephone set.

Offline dsk

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #6 on: November 02, 2014, 12:23:18 PM »
Everything is working, but I have the right exchange, it needs 48v to work properly.
The vault keys are missing, no big problem, managed to remove the lock and turn it upside down, so it looks OK but the drawer are unlocked. 

More info will follow.


dsk

Offline dsk

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #7 on: November 02, 2014, 12:41:07 PM »
Not easy to figure out whats excluded number, this is how it is programmed by soldering:

unbeldi

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #8 on: November 02, 2014, 01:29:02 PM »
Yes, the dial is configured to block certain numbers by installing wire jumpers on the lugs for the corresponding digits. When a digit is blocked, these switches short the dial pulse contacts so dialing that digit is ineffective. I think you have a version of the dial that blocks up to three leading digits, so there  should be three planes of contacts.
In Germany, the first digit of any long-distance call would have been '0', but your dial was probably preconfigured for the local Oslo dial plan.

Offline dsk

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Re: German Tabletop Tin Mu 55b (Hagenuk) Oslo version
« Reply #9 on: November 03, 2014, 06:04:08 AM »
It seems to be suitable for Oslo at that time. The number plan was stertsched to above its limits, and some areas were just in the 02 are, but still long distance.
This type of telephone lost its value when local calls were taxed by time, and not by number of calls.

I managed to make a key for vault lock. (An interesting and time consuming experience.)

dsk

Offline dsk

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Re: German Tabletop Teilnehmer-Münzfernsprecher 55 (Hagenuk) Oslo version
« Reply #10 on: November 04, 2014, 08:05:18 AM »
I have tried to analyze the how the dc current flows trough the unit in different states of operation.
The sound may be heard even in situations where the transmitter have no DC, but you will only be heard when the DC travel trough the transmitter.

Please PM me if I have misspelled something, or you find other errors.

dsk

PS at last I figured out the idea of that polarity sensitive relay, It has nothing to do with polarity reversal, becaus it was not used on lines with that function, it is to prevent people using the weakness of the blocking mechanism. E.g. starting with dialing 3 non blocked digits, then slowly let the dial return, and you would get a new dial tone, then dial whatever... The relay will release on this action, and you loose connection.

DS
« Last Edit: November 04, 2014, 02:54:05 PM by dsk »

Offline dsk

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Re: German Tabletop Teilnehmer-Münzfernsprecher 55 (Hagenuk) Oslo version
« Reply #11 on: December 09, 2014, 01:21:55 PM »
I guess this one will work with a NICKEL to.

dsk