|Intercommunication Table and Wall Telephones
Radial Selector, Single Line Local Battery, Secret System
A secret system is sometimes preferred, and this range of instruments has been specially designed to give secrecy and be entirely free from "cross talk," electrostatic and magnetic induction's.
The case work is of high-class finished hardwood.
The micro-telephone is fitted with an electromagnetic receiver, "inset" transmitter and all-metal hygienic mouthpiece.
The radial selector is of substantial design, positive in action, and does not require either automatic or manual replacement, as a ring can be received with the pointer in any position.
Cards giving full working instructions and having spaces for inserting the names of stations, are supplied. Also a diagram showing how the instruments, cables and batteries are connected up.
Three cells are required at each station up to 500 feet of cable between the two most distant stations, and four cells for over 500 feet of cable.
Overall dimensions 12 x 10 x 6 inches.
When these instruments are required as wall sets a bracket is supplied.
Intercommunication Table and Wall Telephones
These instruments are of exactly the same design and outward appearance as N1640 - N1645 those above, but although secrecy is not given, the circuit and working parts are so arranged that the mischievous listening-in by simply moving the selector arm over the numbers has been guarded against.
Full working instructions are provided, also a diagram showing the necessary connections for installation.
The central battery should be located as near the centre of the system as possible.
Overall dimensions 12.5 x 10.25 x 6 inches.
NOTE - When these instruments are required as wall sets a bracket is supplied.
This arrangement saves customers the necessity of keeping two distinct types in stock.
When these instruments are required to be fixed and used as wall sets we supply a bracket as illustrated.
The shelf is of the same high-class finish hardwood as the instruments. and the
supports are black enamelled iron.
The use of lead-covered cable is strongly recommended for intercommunication telephone installations.
Taken from the Ericsson catalogue, edition 26
Last revised: October 03, 2019