We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
2l6
Radio Broadcast
sists of four i8-gauge copper wires on 1 2-inch hoops. The natural wavelength of the aerial is 325 metres.
The earth system consists of a connection to a water pipe, together with a balanced counterpoise. The aerial-counterpoise is very carefully tuned to the same wavelength as the aerial-earth system. With the inclusion of the counterpoise, the radiation is increased by 33 per cent., giving a total radiation of from i to i .2 amperes.
This description would not be complete without mention of the receiving apparatus of the station. As will be seen from the diagram, there are four valves grouped so that one valve acts as a radio-frequency amplifier passing the increased antenna current into the second valve, where it is rectified and detected. From here the received signals are coupled back with a tickler so as to use the regenerative effect and pass.ed into the third valve which acts as an audio-frequency amplifier. The fourth
valve is a second stage of audio-frequency amplification. In practice, however, one valve only need be used to receive Nauen, Bordeaux, New York, etc.
Another feature of the receiver is the inclusion of an independent oscillator which acts as a heterodyne. In this manner much greater control can be attained with increase in signal strength and correspondingly greater selectivity.
On the night of May 2ist last while conducting some tests in wireless telephony with the Sydney Observatory, using only 9 watts input, Mr. Maclurcan was heard in Melbourne 450 miles away. A telegram was received the following day stating that a Mr. J. Reed and several amateurs in Melbourne had heard the carrier wave on the previous evening.
Mr. Maclurcan then arranged to try to establish definite communication with Mr. Reed, with results entirely satisfactory.
Encouraged with the Melbourne success, Mr.
THE STATION AT STRATHFIELD, NEAR SYDNEY
From which Australians are getting their first broadcasting. Although the transmitter is never operated above 9 watts, it has been heard 2100 miles overland on a single-tube receiver