Name M�nzfernsprecher OM� 57 (Coin Telephone 57)
Maker DBP (Deutsche BundesPost / German Federal Post Office)
Date 1957
Exterior characteristics and traffic possibilities of the MuenzFw 57 resembles outwardly the MuenzFw 56 with the difference that right above the Muenzspeichers a remaining credit balance announcement is arranged . There a possible remainder is represented by 10..... 90 Pf.  If a coin with high order is taken, then lights up the number appropriate, yet used up remainder this coin.  Apart from the traffic possibilities, which the MuenzFw 56 offers, the still following further traffic possibility of preventing illegal connections in the MuenzFw 57 becomes a special form of the SpNrS 55 with the MuenzFw 57, which uses SpNrS 55/57.  This is in such a way modified that with the number ' 0 ' in the first place or on first and second place no control arm is adjusted to the step 10 of a contact field, but that the control arm upon the expiration of the dial runs back into the rest position.  The number of zeros selected in the first places is electrically stored.  With the next selected number this control arm can be consulted again for the evaluation.  Thus an evaluation of maximally five numbers becomes possible with international discussions.  Otherwise the function of the SpNrS is equal to 55/57 that of the SpNrS 55.  Coin examination it is accomplished the same examinations as with the MuenzFw 56.  The minimum charge can be stopped between 10 and 50 Pf.