Tests of the synchronograph on the telegraph lines of the British Government: The wheatstone receiver operated by the alternating current in transmitting intelligence

✍ Scribed by Albert Cushing Crehore; George Owen Squier

• Publisher: Elsevier Science
• Year: 1898
• Tongue: English
• Weight: 756 KB
• Volume: 145
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(98)90272-1

✦ Synopsis

EXPERIMENTS WITH THE ARTIFICIAL CABLE.

Opportunity was presented for preliminary tests of this method of transmitting signals over the artificial cable belonging to the British Post Office Department, and of making direct comparisons of the alternating-current method with the present Wheatstone system over the identical cable. These trials were made on August 2I, I897. This cable, which represents to within I per cent. the real cable such as is used from England to the continent, to Ireland, the Channel Islands, etc., is made in 60 sections of three knots each, making a total of I8o knots or 207" 5 miles. Each section has K equal to I microfarad and R --= 33 ohms, making total K ----60 microfarads and total R ~ 33 X 60 = 1,98o ohms, and total KR = II8,8oo. The cable is of the type in which the distributed capacity is obtained by condensers placed at regular intervals along its length.

Through this cable, with a voltage of I io, messages were sent at a frequency of 93"6 or I87"2 alternations per second, using the synchronograph and the chemical 1:eceiver. The next experiment was with the Wheatstone system transmitter