The Design of German

Telephone Subscribers'Apparatus

BIOS Report No. 606


Reported by


BIOS Trip No. 1533


BIOS Target Nos:

7/57, C7/57i, C7/211, 7/131, C7/277, C7/280, C7/276, 7/26


Keywords:    German standards for exchange service; Maintenance; Telephone Installation Work; Super - posed Wire Broiadcasting (Drahtfunk); General Meachanical features; Trends in electrical and acoustical design; The Anti-Side Tone Circuit (Übersprechen oder Nebensprechen?); Local battery microphones; Transverse current microphones; Regenerative microphone under development by RPF (= Reichspostfurschunsanstalt); Recent developments by Siemens & Halske (S&H); Receiver under development by RPF); Sound powered telephones by Siemens; Operators'Telephone head set with microphone; Telephones for deaf; Telephones for long lines; Subscribers'amplifiers; Auxiliary receiver; Loud speaking telephones; Zweiband system of "4-wire wirking" on single-pair lines; Telephone instrument tester; calibration of receivers; Sound absorbent room; Recording wave analiser; Impedance measuring set; Calibration of condensor microphones; Condenser microphone for explosion measurements; Gramophone recording; Former German Dial; Operator dials; Other impulsing devices; Private-Automatic Branch Exchanges; Multi-Fee working; Relative specifications and police-Orders; Type test of flameproof apparatus; Reports on visits to manufacturers' works; Frequency inversion system for telephone circuits; Band splitting system; Time Scrambling system; Wobble-Frequency system; Reichspost policy for subscribers'apparatus ... ; German telephone instruments differ from their B.P.O. equivalents in the greater use of metal pressing ... ; Formerly the Reichspost examined a small portion of a contract by articulation testing. If these were below standard the whole delivery was returned to the contractor .. ; Mr. Panzerbeiter of Siemens & Halske .. ; Janovsky - Hölzer; The early Siemens & Halske sound telephone was an imitation of Western Electric Co's. instrument and was coded No. 33b ... ; Hagenuk of Kiel were stated to have developed a mechanical amplifier using a crystal receiver copled to a carbon microphone ... ; The Lorenz Zweiband system was contrived so that ... ; "hard ear" ... ; Recording analyser was seen at PTR. This was a development of the design described by Jacobi in W.V.S.K. .. during the war it had been used to analyse records of scrambled telephone speech ... : Synthetic shellac "Troschell" made by I.G. Farbenindustrie .. ; The circuit of the 50- and 100-line lamp-signalling P.M.B.X. switchboards are generally similar to those of the B.P.O. .. ; Large power are now mostly replaced by electromagnetic circuit breakers, whereas individual apparatus circuits are protected by heat coils; Telephone and Radio-telephone privacy equipment ... ; Six or ten pairs of 2-band equipment were supplied by Siemens & Halske to the German Navy for installation in Cruisers. A few pairs of 3-band equipments were provided for radio communication between Berlin and the german Embassies in London and other foreign capitals. A 5-band system with automatic switching was employed the reichspost for transatlantic radio circuits to the U.S. telephone system; Band slitting equipment was regarded by Sacklowski as somwhat better ... ; Wobble-Frequency system was developed for the Luftwaffe on decimetre-wave beam sircuits. ... ; Ohnesorge Reichspost Minister ... ; Atlas-Werke Dr. Blaum works manager of mechanical department - Herr Sommer works manager of electrical department - Dr. Maass physicist and laboratory manager - day of visit 17 th December 1945 ... The main factory is at Bremen, others were at Gnadenfrei (Silesia), Munich and Elmshorn ... ; Ecjo sounders for trawlers .. ; Mass was very proud of a discovery which he claimed was entirely new.  .... ; Speech audiometer of their own design .. ; manufacture of Rochelle salt crystals at Atlas-Werke Elmshorn (target C7/276) ...



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