Wireless Telegraphy and Telephony
Forfatter: Alfred P. Morgan
År: 1917
Forlag: The Norman W. Henley Publishing Company
Sted: New York
Udgave: Third Edition, Fully Illustrated
Sider: 33
UDK: 621.396.1 Mor
A practical Treatise on Wireless Telegraphy and Telephony, giving Complete and Detailed Explanations of the Theory and Practice of Modern Radio Apparatus and its Present Day Applications, together with a chapter on the possibilities of its Future Development
Søgning i bogen
Den bedste måde at søge i bogen er ved at downloade PDF'en og søge i den.
Derved får du fremhævet ordene visuelt direkte på billedet af siden.
Digitaliseret bog
Bogens tekst er maskinlæst, så der kan være en del fejl og mangler.
WIRELESS TELEGRAPHY
25
and conductors. They do not permeate to the center of
the wire, as do normal currents. The surface of a stranded
wire is greater in comparison to its cross-section than a
solid conductor of the same diameter, and therefore is
often employed because it offers less resistance to currents
of this sort.
Fig. 24.—Showing how wires are arranged and insulated.
Aluminum wire is very light, and causes very little strain
on the pole or cross-arms. It offers more resistance than
copper, but some of the larger sizes may be used with
equally good results.
Iron wire must never be used, even if galvanized or
tinned. It possesses a certain reactance tending to choke
off the high frequency currents.
.INSULATING MATERIAL
V'"'- EYE HOLT
Fig. 25.—Aerial insulator.
The aerial is always very carefully insulated from its sup-
ports and surrounding objects by special insulators, capable
of withstanding severe strains, made of a moulded material
having an iron ring imbedded in each end.
Fig. 26.—Leading-in insulator.