Desk payphone 33
The tabletop coin-operated telephone 33 (TiMü 33) is a German telephone with a coin slot . The number 33 stands for the year of construction 1933.
This device is based on the desk telephone W 28 of the Deutsche Reichspost and was mainly used in restaurants , hotels , guest houses and club houses - i.e. in semi-public places. In contrast to the public telephones in telephone booths , the supervision and emptying of the cash box was not the responsibility of the Reichspost, but of the subscriber who kept the inserted money and settled it on his telephone bill. From a legal point of view, this was not a public telephone and could not be marked as such. Colloquially, the TiMü 33 was referred to as "Groschengrab" or "Kneipenmünzer".
The TiMü 33 is only available in black. Telephone receiver , fork and finger hole disk (rotary dial) are similar to the W28. The same goes for the upper part of the housing made of Bakelite and the lower part made of deep-drawn sheet steel - it is longer and higher because of the lockable cash box inserted from the front and the opening for coin insertion. A short instruction manual is attached to the top of the housing above the coin opening. Later copies have a bakelite fork mounted.
function
The TiMü 33 was only approved for local calls. The caller had to have a 10 Reichspfennig coin ready and put it on a slot. Then the number was dialed. If a connection was established, you pushed the coin into the cash box with the left button and released it again. Then the carbon microphone was activated and you could speak. This technically rather simple construction of the coin slot has the disadvantage that any incorrect connections are at the expense of the subscriber if the user did not insert the coins when reporting the person called in error, but hung up. In addition, z. B. by arrangement someone can be called without establishing a mutual speech connection, these - actually chargeable - calls are possible without inserting a coin. Incoming calls can be answered free of charge as usual. The subscriber was given two keys - one to empty the cassette and one to unlock the device so that it can be used like a conventional telephone. The first versions of the TiMü 33 were made with simple locks, later versions have so-called cruciform locks .
The complex mechanics of the number switch prevented long-distance calls and calls to the operator . The first three digits, the "0" and the sequence are controlled by special contacts in connection with switching gates and blocked if necessary ( locking number switch ). Artificially braking the dial immediately blocks the dialing process. This type of number switch was also used in the public payphones , e.g. B. in the local coin phone 33 (O Mü 33) - it is based on the N30 used in the W28 from 1930. In order to prevent blocked numbers from being dialed by tapping the fork briefly ("fork selection"), this is delayed by approx. One second by a small air pump. When you hang up the handset, the dial is blocked (as with the W28) and the number switch is automatically reset.
The listening / speaking circuit of the TiMü 33 largely corresponds to the W28. Except for the number switch and the fork, all components are mounted in the lower part of the housing and freely wired with bound cable harnesses . The device was used and repaired until the 1950s, in some cases even later, also in the former GDR . The coin slot has been converted to 2x 10 Pfennig coins. The successor model was the technically improved subscriber coin-operated telephone 55b, constructed in 1955 .
The TiMü 33 is a popular collector's item today. However, visually well-preserved copies in the original Reichspost condition are rarely available, especially with a complete set of keys. These devices are still functional, you need a main connection or a telephone system that supports the pulse dialing process . In most cases an overhaul of the locking number switch is necessary (resinified lubrication, weak springs, oxidized contacts).