Published Resources Details
Journal Article
- Title
- The design of an automatic variable-frequency radio transmitter with automatically tuned receiver, for use in the investigation of radio propagation in the Ionosphere
- In
- Journal of the Institution of Engineers, Australia
- Imprint
- vol. 8, no. 11, Nov 1936, pp. 403-414
- ISBN/ISSN
- 0020-3319
- Description
This paper, No. 576, originated in the Sydney Division of The Institution.
[This paper was awarded the Electrical Association Premium 1936.]
[The author, Herbert Boyne Wood BE BSc AMIEAust, was commissioned in October 1935 to undertake this research by the Commonwealth Radio Research Board, Council for Scientific and Industrial Research.]
- Abstract
The paper describes the design of a pulse-modulated radio transmitter, the frequency of which is automatically, and recurrently, varied from 1.6 to 10 Mc./s. at a constant rate of 28 kc./s. per second, together with a superheterodyne receiver which is automatically tuned to the transmitter. The output from the receiver is applied to a cathode-ray oscillograph, and the resulting ground pulse and echo pattern is recorded by an automatically controlled camera. A new method of calibration of the records, involving the use of de-focussing of the oscillograph, is described.
The apparatus continuously records variations of the effective height and ionisation density of the various reflecting layers. Apart from its purely scientific value, the information thus obtained will be of great value in predicting the operating wave-lengths in short-wave wireless communication at different times of the day and year.