LONG DISTANCE PHONE IMPROVED BY RESEARCH

Manawatu Times, Volume LIV, Issue 6805, 8 January 1929, Page 3

LONG DISTANCE PHONE IMPROVED BY RESEARCH

VALUABLE NEW METAL. A new metal known as “•penninvar” which is expected to aid long distance telephone transmission, has just been exhibited at Baltimore by Sergius P. Grace, assistant vice-president of the Bell Telephone Laboratories. The new metal, Mr Grace said, is oae of many improvements resulting from extensive research dealing with many technical problems in which the laboratories are at present engaged. Tho (studies, he added, are no longer undertaken by only a few experts, but arc pursued by a large corps of specialists. The research specialists, engineers and assistants in the Bell Laboratories, he added, now number 4000.

Perm-invar, according to Mr Grace, is a combination of cobalt iron and nickel, to which, special hea.t treatment is given to bring out super-magnetic qualities. It is used in the making of “loading coils” for telephone cable circuits.

The “loading” of telephone circuits, Mr Grace added, represents one of tho outstanding achievements in the research sponsored by the Bell system, and has resulted in savings in plant investment of “fully one-third of a billion dollars.”

The function of a loading coil and telephone repeater is to enable conversation to be earned over long distances by -wires no larger in diameter than an ordinary pin.' Under the old method of operation, copper wires nearly the size of lead ’pencils were strung on poles. Mr Grace demonstrated a “delayed speech” device which is being used on transoceanic radio ciricuits where it is necessary lo allow certain contact closing devices to operate prior to the actual transmission of the electrical speech waves. The device “holds up” the words for two-hundredths of a second. This accomplishment, it was said, is comparable to slowing down an airplane to four miles an hour. The electrical action, lie said, is approximately the same as the “slowing down” of a mechanical impulse by transmitting it tli rough a coiled spring instead of tiausmitting it by direct contact.