German Field Telephone Batteries, WWII Tactical and Technical Trends, No. 35, October 7, 1943 (Lone Sentry)

It has been reported from a German source considered to be well informed, that the batteries used for field telephones in Africa contained acid of which the specific gravity was 24°, Baume.* For service in extreme heat, this figure is reduced, while in Europe it would be 27° or 28°. The batteries were made of wood, lined with an acid-proof matrix described as "pitch - tar mould". The voltage for telephone use was stated as 1.5. After six months, the batteries became exhausted. They resembled a single cell from a pocket flashlight battery, of the type which usually has 4.5 volts. In this particular case, the cell was enlarged for greater amperage.

The German signal corps is reported to be furnished with a field live-testing set, battery operated, which can measure voltages as high as 300 amps, also resistance. It can be used to test lines and elements, with or without load.

From the same source as the previous item comes an account of a special cable covered with synthetic rubber, over which a tank can pass without injuring it. Such cable is supplied in drums of 273 yards length. To lay, a truck would drive the length of the cable on the drum, unreeling the cable, which is then connected with the second drum, and the truck proceeds. It was stated that in this way 2 or 3 km (1.22 to 1.86 miles) of cable could be laid in from 20 minutes to half an hour.

The cable is reported to carry two pairs, which, it was stated, could be used for multi-channel traffic for both teletype and telephone.

*Equivalent to 1.199 specific gravity.